diff --git a/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel_exemplars/greeting/GreetingServlet.java b/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel_exemplars/greeting/GreetingServlet.java
index 2fd266cd9..a1046e2a2 100644
--- a/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel_exemplars/greeting/GreetingServlet.java
+++ b/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel_exemplars/greeting/GreetingServlet.java
@@ -27,7 +27,7 @@ public GreetingServlet() {
             .withUnit(Unit.SECONDS)
             .withLabelNames("http_status")
             .register();
-        histogram.withLabelValues("200");
+        histogram.initLabelValues("200");
     }
 
     @Override
diff --git a/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel_exemplars/app/HelloWorldServlet.java b/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel_exemplars/app/HelloWorldServlet.java
index d7c5db034..cabedbce5 100644
--- a/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel_exemplars/app/HelloWorldServlet.java
+++ b/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel_exemplars/app/HelloWorldServlet.java
@@ -34,7 +34,7 @@ public HelloWorldServlet() {
                 .withUnit(Unit.SECONDS)
                 .withLabelNames("http_status")
                 .register();
-        histogram.withLabelValues("200");
+        histogram.initLabelValues("200");
     }
 
     @Override
diff --git a/examples/example-tomcat-servlet/src/main/java/io/prometheus/metrics/examples/tomcat_servlet/HelloWorldServlet.java b/examples/example-tomcat-servlet/src/main/java/io/prometheus/metrics/examples/tomcat_servlet/HelloWorldServlet.java
index 1598028db..7a95e36da 100644
--- a/examples/example-tomcat-servlet/src/main/java/io/prometheus/metrics/examples/tomcat_servlet/HelloWorldServlet.java
+++ b/examples/example-tomcat-servlet/src/main/java/io/prometheus/metrics/examples/tomcat_servlet/HelloWorldServlet.java
@@ -32,6 +32,11 @@ public class HelloWorldServlet extends HttpServlet {
             .withLabelNames("http_status")
             .register();
 
+    public HelloWorldServlet() {
+        counter.initLabelValues("200");
+        histogram.initLabelValues("200");
+    }
+
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
         long start = System.nanoTime();
diff --git a/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusProperties.java b/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusProperties.java
index 9341c5988..95660a463 100644
--- a/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusProperties.java
+++ b/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusProperties.java
@@ -58,7 +58,7 @@ public MetricsProperties getDefaultMetricProperties() {
      * May return {@code null} if no metric-specific properties are configured for a metric name.
      */
     public MetricsProperties getMetricProperties(String metricName) {
-        return metricProperties.get(metricName);
+        return metricProperties.get(metricName.replace(".", "_"));
     }
 
     public ExemplarsProperties getExemplarProperties() {
diff --git a/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusPropertiesLoader.java b/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusPropertiesLoader.java
index ba52372e5..58ddc2669 100644
--- a/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusPropertiesLoader.java
+++ b/prometheus-metrics-config/src/main/java/io/prometheus/metrics/config/PrometheusPropertiesLoader.java
@@ -39,6 +39,8 @@ public static PrometheusProperties load() throws PrometheusPropertiesException {
     // This will remove entries from properties when they are processed.
     private static Map<String, MetricsProperties> loadMetricsConfigs(Map<Object, Object> properties) {
         Map<String, MetricsProperties> result = new HashMap<>();
+        // Note that the metric name in the properties file must be as exposed in the Prometheus exposition formats,
+        // i.e. all dots replaced with underscores.
         Pattern pattern = Pattern.compile("io\\.prometheus\\.metrics\\.([^.]+)\\.");
         // Create a copy of the keySet() for iterating. We cannot iterate directly over keySet()
         // because entries are removed when MetricsConfig.load(...) is called.
@@ -49,7 +51,7 @@ private static Map<String, MetricsProperties> loadMetricsConfigs(Map<Object, Obj
         for (String propertyName : propertyNames) {
             Matcher matcher = pattern.matcher(propertyName);
             if (matcher.find()) {
-                String metricName = matcher.group(1);
+                String metricName = matcher.group(1).replace(".", "_");
                 if (!result.containsKey(metricName)) {
                     result.put(metricName, MetricsProperties.load("io.prometheus.metrics." + metricName, properties));
                 }
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Counter.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Counter.java
index 6b5301cc5..caf2cf854 100644
--- a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Counter.java
+++ b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Counter.java
@@ -9,6 +9,7 @@
 import io.prometheus.metrics.model.snapshots.CounterSnapshot;
 import io.prometheus.metrics.model.snapshots.Exemplar;
 import io.prometheus.metrics.model.snapshots.Labels;
+import io.prometheus.metrics.model.snapshots.PrometheusNaming;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -16,6 +17,8 @@
 import java.util.concurrent.atomic.DoubleAdder;
 import java.util.concurrent.atomic.LongAdder;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
+
 /**
  * Counter metric.
  * <p>
@@ -109,8 +112,8 @@ protected CounterSnapshot collect(List<Labels> labels, List<DataPoint> metricDat
         return new CounterSnapshot(getMetadata(), data);
     }
 
-    static String normalizeName(String name) {
-        if (name != null && name.endsWith("_total")) {
+    static String stripTotalSuffix(String name) {
+        if (name != null && (name.endsWith("_total") || name.endsWith(".total"))) {
             name = name.substring(0, name.length() - 6);
         }
         return name;
@@ -231,12 +234,12 @@ private Builder(PrometheusProperties properties) {
          * In the example above both {@code c1} and {@code c2} would be named {@code "events_total"} in Prometheus.
          * <p>
          * Throws an {@link IllegalArgumentException} if
-         * {@link io.prometheus.metrics.model.snapshots.MetricMetadata#isValidMetricName(String) MetricMetadata.isValidMetricName(name)}
+         * {@link io.prometheus.metrics.model.snapshots.PrometheusNaming#isValidMetricName(String) MetricMetadata.isValidMetricName(name)}
          * is {@code false}.
          */
         @Override
         public Builder withName(String name) {
-            return super.withName(normalizeName(name));
+            return super.withName(stripTotalSuffix(name));
         }
 
         @Override
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/CounterWithCallback.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/CounterWithCallback.java
index c7446f4c1..b4d7bc761 100644
--- a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/CounterWithCallback.java
+++ b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/CounterWithCallback.java
@@ -80,12 +80,12 @@ private Builder(PrometheusProperties properties) {
          * In the example above both {@code c1} and {@code c2} would be named {@code "events_total"} in Prometheus.
          * <p>
          * Throws an {@link IllegalArgumentException} if
-         * {@link io.prometheus.metrics.model.snapshots.MetricMetadata#isValidMetricName(String) MetricMetadata.isValidMetricName(name)}
+         * {@link io.prometheus.metrics.model.snapshots.PrometheusNaming#isValidMetricName(String) MetricMetadata.isValidMetricName(name)}
          * is {@code false}.
          */
         @Override
         public Builder withName(String name) {
-            return super.withName(Counter.normalizeName(name));
+            return super.withName(Counter.stripTotalSuffix(name));
         }
 
         @Override
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Info.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Info.java
index 9d6675dbb..5731e2843 100644
--- a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Info.java
+++ b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Info.java
@@ -2,16 +2,16 @@
 
 import io.prometheus.metrics.config.PrometheusProperties;
 import io.prometheus.metrics.model.snapshots.InfoSnapshot;
-import io.prometheus.metrics.model.snapshots.Label;
 import io.prometheus.metrics.model.snapshots.Labels;
 import io.prometheus.metrics.model.snapshots.Unit;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
+
 /**
  * Info metric. Example:
  * <pre>{@code
@@ -90,15 +90,12 @@ private Builder(PrometheusProperties config) {
          * In the example above both {@code info1} and {@code info2} will be named {@code "runtime_info"} in Prometheus.
          * <p>
          * Throws an {@link IllegalArgumentException} if
-         * {@link io.prometheus.metrics.model.snapshots.MetricMetadata#isValidMetricName(String) MetricMetadata.isValidMetricName(name)}
+         * {@link io.prometheus.metrics.model.snapshots.PrometheusNaming#isValidMetricName(String) MetricMetadata.isValidMetricName(name)}
          * is {@code false}.
          */
         @Override
         public Builder withName(String name) {
-            if (name != null && name.endsWith("_info")) {
-                name = name.substring(0, name.length() - 5);
-            }
-            return super.withName(name);
+            return super.withName(stripInfoSuffix(name));
         }
 
         /**
@@ -112,8 +109,8 @@ public Builder withUnit(Unit unit) {
             return this;
         }
 
-        private static String normalizeName(String name) {
-            if (name != null && name.endsWith("_info")) {
+        private static String stripInfoSuffix(String name) {
+            if (name != null && (name.endsWith("_info") || name.endsWith(".info"))) {
                 name = name.substring(0, name.length() - 5);
             }
             return name;
@@ -121,7 +118,7 @@ private static String normalizeName(String name) {
 
         @Override
         public Info build() {
-            return new Info(withName(normalizeName(name)));
+            return new Info(this);
         }
 
         @Override
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/MetricWithFixedMetadata.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/MetricWithFixedMetadata.java
index 22b607654..6f963c299 100644
--- a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/MetricWithFixedMetadata.java
+++ b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/MetricWithFixedMetadata.java
@@ -3,11 +3,14 @@
 import io.prometheus.metrics.config.PrometheusProperties;
 import io.prometheus.metrics.model.snapshots.Labels;
 import io.prometheus.metrics.model.snapshots.MetricMetadata;
+import io.prometheus.metrics.model.snapshots.PrometheusNaming;
 import io.prometheus.metrics.model.snapshots.Unit;
 
 import java.util.Arrays;
 import java.util.List;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
+
 /**
  * Almost all metrics have fixed metadata, i.e. the metric name is known when the metric is created.
  * <p>
@@ -31,9 +34,8 @@ protected MetricMetadata getMetadata() {
 
     private String makeName(String name, Unit unit) {
         if (unit != null) {
-            String suffix = "_" + unit;
-            if (!name.endsWith(suffix)) {
-                name = name + suffix;
+            if (!name.endsWith(unit.toString())) {
+                name = name + "_" + unit;
             }
         }
         return name;
@@ -51,7 +53,7 @@ protected Builder(List<String> illegalLabelNames, PrometheusProperties propertie
         }
 
         public B withName(String name) {
-            if (!MetricMetadata.isValidMetricName(name)) {
+            if (!PrometheusNaming.isValidMetricName(name)) {
                 throw new IllegalArgumentException("'" + name + "': Illegal metric name.");
             }
             this.name = name;
@@ -70,7 +72,7 @@ public B withHelp(String help) {
 
         public B withLabelNames(String... labelNames) {
             for (String labelName : labelNames) {
-                if (!Labels.isValidLabelName(labelName)) {
+                if (!PrometheusNaming.isValidLabelName(labelName)) {
                     throw new IllegalArgumentException(labelName + ": illegal label name");
                 }
                 if (illegalLabelNames.contains(labelName)) {
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StateSet.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StateSet.java
index 308c61be1..7348c0410 100644
--- a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StateSet.java
+++ b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StateSet.java
@@ -3,6 +3,7 @@
 import io.prometheus.metrics.config.MetricsProperties;
 import io.prometheus.metrics.config.PrometheusProperties;
 import io.prometheus.metrics.model.snapshots.Labels;
+import io.prometheus.metrics.model.snapshots.MetricMetadata;
 import io.prometheus.metrics.model.snapshots.StateSetSnapshot;
 import io.prometheus.metrics.core.datapoints.StateSetDataPoint;
 
@@ -11,6 +12,8 @@
 import java.util.List;
 import java.util.stream.Stream;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
+
 /**
  * StateSet metric. Example:
  * <pre>{@code
@@ -58,7 +61,7 @@ private StateSet(Builder builder, PrometheusProperties prometheusProperties) {
         exemplarsEnabled = getConfigProperty(properties, MetricsProperties::getExemplarsEnabled);
         this.names = builder.names; // builder.names is already a validated copy
         for (String name : names) {
-            if (this.getMetadata().getName().equals(name)) {
+            if (this.getMetadata().getPrometheusName().equals(prometheusName(name))) {
                 throw new IllegalArgumentException("Label name " + name + " is illegal (can't use the metric name as label name in state set metrics)");
             }
         }
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StatefulMetric.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StatefulMetric.java
index 591c16e6b..17d8da246 100644
--- a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StatefulMetric.java
+++ b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/StatefulMetric.java
@@ -62,6 +62,34 @@ public MetricSnapshot collect() {
         return collect(labels, metricData);
     }
 
+    /**
+     * Initialize label values.
+     * <p>
+     * Example: Imagine you have a counter for payments as follows
+     * <pre>
+     * payment_transactions_total{payment_type="credit card"} 7.0
+     * payment_transactions_total{payment_type="paypal"} 3.0
+     * </pre>
+     * Now, the data points for the {@code payment_type} label values get initialized when they are
+     * first used, i.e. the first time you call
+     * <pre>{@code
+     * counter.withLabelValues("paypal").inc();
+     * }</pre>
+     * the data point with label {@code payment_type="paypal"} will go from non-existent to having value {@code 1.0}.
+     * <p>
+     * In some cases this is confusing, and you want to have data points initialized on application start
+     * with an initial value of {@code 0.0}:
+     * <pre>
+     * payment_transactions_total{payment_type="credit card"} 0.0
+     * payment_transactions_total{payment_type="paypal"} 0.0
+     * </pre>
+     * {@code initLabelValues(...)} can be used to initialize label value, so that the data points
+     * show up in the exposition format with an initial value of zero.
+     */
+    public void initLabelValues(String... labelValues) {
+        withLabelValues(labelValues);
+    }
+
     public D withLabelValues(String... labelValues) {
         if (labelValues.length != labelNames.length) {
             if (labelValues.length == 0) {
@@ -73,7 +101,6 @@ public D withLabelValues(String... labelValues) {
         return data.computeIfAbsent(Arrays.asList(labelValues), l -> newDataPoint());
     }
 
-    // TODO: Remove automatically if label values have not been used in a while?
     public void remove(String... labelValues) {
         data.remove(Arrays.asList(labelValues));
     }
diff --git a/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/CounterTest.java b/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/CounterTest.java
index 0efa6ee4a..a967a8d64 100644
--- a/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/CounterTest.java
+++ b/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/CounterTest.java
@@ -109,18 +109,18 @@ public void testLabels() {
 
     @Test
     public void testTotalStrippedFromName() {
-        Counter counter = Counter.newBuilder()
-                .withName("my_counter_total")
-                .withUnit(Unit.SECONDS)
-                .build();
-        Metrics.MetricFamily protobufData = new PrometheusProtobufWriter().convert(counter.collect());
-        assertEquals("name: \"my_counter_seconds_total\" type: COUNTER metric { counter { value: 0.0 } }", TextFormat.printer().shortDebugString(protobufData));
-
-        counter = Counter.newBuilder()
-                .withName("my_counter")
-                .build();
-        protobufData = new PrometheusProtobufWriter().convert(counter.collect());
-        assertEquals("name: \"my_counter_total\" type: COUNTER metric { counter { value: 0.0 } }", TextFormat.printer().shortDebugString(protobufData));
+        for (String name : new String[]{
+                "my_counter_total", "my.counter.total",
+                "my_counter_seconds_total", "my.counter.seconds.total",
+                "my_counter", "my.counter",
+                "my_counter_seconds", "my.counter.seconds"}) {
+            Counter counter = Counter.newBuilder()
+                    .withName(name)
+                    .withUnit(Unit.SECONDS)
+                    .build();
+            Metrics.MetricFamily protobufData = new PrometheusProtobufWriter().convert(counter.collect());
+            assertEquals("name: \"my_counter_seconds_total\" type: COUNTER metric { counter { value: 0.0 } }", TextFormat.printer().shortDebugString(protobufData));
+        }
     }
 
     @Test
diff --git a/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/HistogramTest.java b/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/HistogramTest.java
index 393e2c876..2af392097 100644
--- a/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/HistogramTest.java
+++ b/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/HistogramTest.java
@@ -1,19 +1,19 @@
 package io.prometheus.metrics.core.metrics;
 
 import io.prometheus.metrics.com_google_protobuf_3_21_7.TextFormat;
+import io.prometheus.metrics.core.datapoints.DistributionDataPoint;
+import io.prometheus.metrics.core.exemplars.ExemplarSamplerConfigTestUtil;
 import io.prometheus.metrics.expositionformats.OpenMetricsTextFormatWriter;
 import io.prometheus.metrics.expositionformats.PrometheusProtobufWriter;
 import io.prometheus.metrics.expositionformats.generated.com_google_protobuf_3_21_7.Metrics;
-import io.prometheus.metrics.core.exemplars.ExemplarSamplerConfigTestUtil;
-import io.prometheus.metrics.model.snapshots.MetricSnapshots;
-import io.prometheus.metrics.tracer.common.SpanContext;
-import io.prometheus.metrics.tracer.initializer.SpanContextSupplier;
 import io.prometheus.metrics.model.snapshots.ClassicHistogramBucket;
 import io.prometheus.metrics.model.snapshots.Exemplar;
 import io.prometheus.metrics.model.snapshots.Exemplars;
 import io.prometheus.metrics.model.snapshots.HistogramSnapshot;
 import io.prometheus.metrics.model.snapshots.Labels;
-import io.prometheus.metrics.core.datapoints.DistributionDataPoint;
+import io.prometheus.metrics.model.snapshots.MetricSnapshots;
+import io.prometheus.metrics.tracer.common.SpanContext;
+import io.prometheus.metrics.tracer.initializer.SpanContextSupplier;
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
@@ -1043,19 +1043,9 @@ public void testIllegalLabelNamePrefix() {
                 .withLabelNames("__hello");
     }
 
-    @Test(expected = IllegalArgumentException.class)
-    public void testIllegalLabelNameDot() {
-        // The Prometheus team are investigating to allow dots in future Prometheus versions, but for now it's invalid.
-        // The reason is that you cannot use illegal label names in the Prometheus query language.
-        Histogram.newBuilder()
-                .withName("test")
-                .withLabelNames("http.status");
-    }
-
     @Test(expected = IllegalArgumentException.class)
     public void testIllegalName() {
-        Histogram.newBuilder()
-                .withName("server.durations");
+        Histogram.newBuilder().withName("my_namespace/server.durations");
     }
 
     @Test(expected = IllegalArgumentException.class)
diff --git a/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/InfoTest.java b/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/InfoTest.java
index 4cca37ef6..5b1bbf991 100644
--- a/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/InfoTest.java
+++ b/prometheus-metrics-core/src/test/java/io/prometheus/metrics/core/metrics/InfoTest.java
@@ -1,23 +1,28 @@
 package io.prometheus.metrics.core.metrics;
 
-import io.prometheus.metrics.model.snapshots.InfoSnapshot;
-import io.prometheus.metrics.model.snapshots.Labels;
-import org.junit.Assert;
+import io.prometheus.metrics.com_google_protobuf_3_21_7.TextFormat;
+import io.prometheus.metrics.expositionformats.PrometheusProtobufWriter;
+import io.prometheus.metrics.expositionformats.generated.com_google_protobuf_3_21_7.Metrics;
 import org.junit.Test;
 
+import static org.junit.Assert.assertEquals;
+
 public class InfoTest {
 
     @Test
-    public void testIncrement() {
-        Info info = Info.newBuilder()
-                .withName("target_info")
-                .withLabelNames("key")
-                .build();
-        info.infoLabelValues("value");
-        InfoSnapshot snapshot = info.collect();
-        Assert.assertEquals("target", snapshot.getMetadata().getName());
-        Assert.assertEquals(1, snapshot.getData().size());
-        InfoSnapshot.InfoDataPointSnapshot data = snapshot.getData().stream().findAny().orElseThrow(RuntimeException::new);
-        Assert.assertEquals(Labels.of("key", "value"), data.getLabels());
+    public void testInfoStrippedFromName() {
+        for (String name : new String[]{
+                "jvm.runtime", "jvm_runtime",
+                "jvm.runtime.info", "jvm_runtime_info"}) {
+            for (String labelName : new String[]{"my.key", "my_key"}) {
+                Info info = Info.newBuilder()
+                        .withName(name)
+                        .withLabelNames(labelName)
+                        .build();
+                info.infoLabelValues("value");
+                Metrics.MetricFamily protobufData = new PrometheusProtobufWriter().convert(info.collect());
+                assertEquals("name: \"jvm_runtime_info\" type: GAUGE metric { label { name: \"my_key\" value: \"value\" } gauge { value: 1.0 } }", TextFormat.printer().shortDebugString(protobufData));
+            }
+        }
     }
 }
diff --git a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/OpenMetricsTextFormatWriter.java b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/OpenMetricsTextFormatWriter.java
index 0559ce0be..fa131335e 100644
--- a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/OpenMetricsTextFormatWriter.java
+++ b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/OpenMetricsTextFormatWriter.java
@@ -29,6 +29,7 @@
 import static io.prometheus.metrics.expositionformats.TextFormatUtil.writeLabels;
 import static io.prometheus.metrics.expositionformats.TextFormatUtil.writeLong;
 import static io.prometheus.metrics.expositionformats.TextFormatUtil.writeTimestamp;
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
 
 /**
  * Write the OpenMetrics text format as defined on <a href="https://openmetrics.io/">https://openmetrics.io</a>.
@@ -89,7 +90,7 @@ private void writeCounter(OutputStreamWriter writer, CounterSnapshot snapshot) t
         MetricMetadata metadata = snapshot.getMetadata();
         writeMetadata(writer, "counter", metadata);
         for (CounterSnapshot.CounterDataPointSnapshot data : snapshot.getData()) {
-            writeNameAndLabels(writer, metadata.getName(), "_total", data.getLabels());
+            writeNameAndLabels(writer, metadata.getPrometheusName(), "_total", data.getLabels());
             writeDouble(writer, data.getValue());
             writeScrapeTimestampAndExemplar(writer, data, data.getExemplar());
             writeCreated(writer, metadata, data);
@@ -100,7 +101,7 @@ private void writeGauge(OutputStreamWriter writer, GaugeSnapshot snapshot) throw
         MetricMetadata metadata = snapshot.getMetadata();
         writeMetadata(writer, "gauge", metadata);
         for (GaugeSnapshot.GaugeDataPointSnapshot data : snapshot.getData()) {
-            writeNameAndLabels(writer, metadata.getName(), null, data.getLabels());
+            writeNameAndLabels(writer, metadata.getPrometheusName(), null, data.getLabels());
             writeDouble(writer, data.getValue());
             if (exemplarsOnAllMetricTypesEnabled) {
                 writeScrapeTimestampAndExemplar(writer, data, data.getExemplar());
@@ -128,7 +129,7 @@ private void writeClassicHistogramBuckets(OutputStreamWriter writer, MetricMetad
             long cumulativeCount = 0;
             for (int i = 0; i < buckets.size(); i++) {
                 cumulativeCount += buckets.getCount(i);
-                writeNameAndLabels(writer, metadata.getName(), "_bucket", data.getLabels(), "le", buckets.getUpperBound(i));
+                writeNameAndLabels(writer, metadata.getPrometheusName(), "_bucket", data.getLabels(), "le", buckets.getUpperBound(i));
                 writeLong(writer, cumulativeCount);
                 Exemplar exemplar;
                 if (i == 0) {
@@ -176,7 +177,7 @@ private void writeSummary(OutputStreamWriter writer, SummarySnapshot snapshot) t
             // quantiles, all indexes modulo exemplars.length.
             int exemplarIndex = 1;
             for (Quantile quantile : data.getQuantiles()) {
-                writeNameAndLabels(writer, metadata.getName(), null, data.getLabels(), "quantile", quantile.getQuantile());
+                writeNameAndLabels(writer, metadata.getPrometheusName(), null, data.getLabels(), "quantile", quantile.getQuantile());
                 writeDouble(writer, quantile.getValue());
                 if (exemplars.size() > 0 && exemplarsOnAllMetricTypesEnabled) {
                     exemplarIndex = (exemplarIndex + 1) % exemplars.size();
@@ -195,7 +196,7 @@ private void writeInfo(OutputStreamWriter writer, InfoSnapshot snapshot) throws
         MetricMetadata metadata = snapshot.getMetadata();
         writeMetadata(writer, "info", metadata);
         for (InfoSnapshot.InfoDataPointSnapshot data : snapshot.getData()) {
-            writeNameAndLabels(writer, metadata.getName(), "_info", data.getLabels());
+            writeNameAndLabels(writer, metadata.getPrometheusName(), "_info", data.getLabels());
             writer.write("1");
             writeScrapeTimestampAndExemplar(writer, data, null);
         }
@@ -206,13 +207,13 @@ private void writeStateSet(OutputStreamWriter writer, StateSetSnapshot snapshot)
         writeMetadata(writer, "stateset", metadata);
         for (StateSetSnapshot.StateSetDataPointSnapshot data : snapshot.getData()) {
             for (int i = 0; i < data.size(); i++) {
-                writer.write(metadata.getName());
+                writer.write(metadata.getPrometheusName());
                 writer.write('{');
                 for (int j = 0; j < data.getLabels().size(); j++) {
                     if (j > 0) {
                         writer.write(",");
                     }
-                    writer.write(data.getLabels().getName(j));
+                    writer.write(data.getLabels().getPrometheusName(j));
                     writer.write("=\"");
                     writeEscapedLabelValue(writer, data.getLabels().getValue(j));
                     writer.write("\"");
@@ -220,7 +221,7 @@ private void writeStateSet(OutputStreamWriter writer, StateSetSnapshot snapshot)
                 if (!data.getLabels().isEmpty()) {
                     writer.write(",");
                 }
-                writer.write(metadata.getName());
+                writer.write(metadata.getPrometheusName());
                 writer.write("=\"");
                 writeEscapedLabelValue(writer, data.getName(i));
                 writer.write("\"} ");
@@ -238,7 +239,7 @@ private void writeUnknown(OutputStreamWriter writer, UnknownSnapshot snapshot) t
         MetricMetadata metadata = snapshot.getMetadata();
         writeMetadata(writer, "unknown", metadata);
         for (UnknownSnapshot.UnknownDataPointSnapshot data : snapshot.getData()) {
-            writeNameAndLabels(writer, metadata.getName(), null, data.getLabels());
+            writeNameAndLabels(writer, metadata.getPrometheusName(), null, data.getLabels());
             writeDouble(writer, data.getValue());
             if (exemplarsOnAllMetricTypesEnabled) {
             writeScrapeTimestampAndExemplar(writer, data, data.getExemplar());
@@ -251,7 +252,7 @@ private void writeUnknown(OutputStreamWriter writer, UnknownSnapshot snapshot) t
     private void writeCountAndSum(OutputStreamWriter writer, MetricMetadata metadata, DistributionDataPointSnapshot data, String countSuffix, String sumSuffix, Exemplars exemplars) throws IOException {
         int exemplarIndex = 0;
         if (data.hasCount()) {
-            writeNameAndLabels(writer, metadata.getName(), countSuffix, data.getLabels());
+            writeNameAndLabels(writer, metadata.getPrometheusName(), countSuffix, data.getLabels());
             writeLong(writer, data.getCount());
             if (exemplars.size() > 0) {
                 writeScrapeTimestampAndExemplar(writer, data, exemplars.get(exemplarIndex));
@@ -261,7 +262,7 @@ private void writeCountAndSum(OutputStreamWriter writer, MetricMetadata metadata
             }
         }
         if (data.hasSum()) {
-            writeNameAndLabels(writer, metadata.getName(), sumSuffix, data.getLabels());
+            writeNameAndLabels(writer, metadata.getPrometheusName(), sumSuffix, data.getLabels());
             writeDouble(writer, data.getSum());
             if (exemplars.size() > 0) {
                 writeScrapeTimestampAndExemplar(writer, data, exemplars.get(exemplarIndex));
@@ -273,7 +274,7 @@ private void writeCountAndSum(OutputStreamWriter writer, MetricMetadata metadata
 
     private void writeCreated(OutputStreamWriter writer, MetricMetadata metadata, DataPointSnapshot data) throws IOException {
         if (createdTimestampsEnabled && data.hasCreatedTimestamp()) {
-            writeNameAndLabels(writer, metadata.getName(), "_created", data.getLabels());
+            writeNameAndLabels(writer, metadata.getPrometheusName(), "_created", data.getLabels());
             writeTimestamp(writer, data.getCreatedTimestampMillis());
             if (data.hasScrapeTimestamp()) {
                 writer.write(' ');
@@ -319,20 +320,20 @@ private void writeScrapeTimestampAndExemplar(OutputStreamWriter writer, DataPoin
 
     private void writeMetadata(OutputStreamWriter writer, String typeName, MetricMetadata metadata) throws IOException {
         writer.write("# TYPE ");
-        writer.write(metadata.getName());
+        writer.write(metadata.getPrometheusName());
         writer.write(' ');
         writer.write(typeName);
         writer.write('\n');
         if (metadata.getUnit() != null) {
             writer.write("# UNIT ");
-            writer.write(metadata.getName());
+            writer.write(metadata.getPrometheusName());
             writer.write(' ');
             writeEscapedLabelValue(writer, metadata.getUnit().toString());
             writer.write('\n');
         }
         if (metadata.getHelp() != null && !metadata.getHelp().isEmpty()) {
             writer.write("# HELP ");
-            writer.write(metadata.getName());
+            writer.write(metadata.getPrometheusName());
             writer.write(' ');
             writeEscapedLabelValue(writer, metadata.getHelp());
             writer.write('\n');
diff --git a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriter.java b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriter.java
index d6de08114..6f4eb6e67 100644
--- a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriter.java
+++ b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriter.java
@@ -24,6 +24,7 @@
 import java.io.OutputStream;
 
 import static io.prometheus.metrics.expositionformats.ProtobufUtil.timestampFromMillis;
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
 
 /**
  * Write the Prometheus protobuf format as defined in
@@ -103,7 +104,7 @@ public Metrics.MetricFamily convert(MetricSnapshot snapshot) {
         } else if (snapshot instanceof StateSetSnapshot) {
             for (StateSetSnapshot.StateSetDataPointSnapshot data : ((StateSetSnapshot) snapshot).getData()) {
                 for (int i = 0; i < data.size(); i++) {
-                    builder.addMetric(convert(data, snapshot.getMetadata().getName(), i));
+                    builder.addMetric(convert(data, snapshot.getMetadata().getPrometheusName(), i));
                 }
             }
             setMetadataUnlessEmpty(builder, snapshot.getMetadata(), null, Metrics.MetricType.GAUGE);
@@ -121,9 +122,9 @@ private void setMetadataUnlessEmpty(Metrics.MetricFamily.Builder builder, Metric
             return;
         }
         if (nameSuffix == null) {
-            builder.setName(metadata.getName());
+            builder.setName(metadata.getPrometheusName());
         } else {
-            builder.setName(metadata.getName() + nameSuffix);
+            builder.setName(metadata.getPrometheusName() + nameSuffix);
         }
         if (metadata.getHelp() != null) {
             builder.setHelp(metadata.getHelp());
@@ -335,7 +336,7 @@ private Metrics.Metric.Builder convert(UnknownSnapshot.UnknownDataPointSnapshot
     private void addLabels(Metrics.Metric.Builder metricBuilder, Labels labels) {
         for (int i = 0; i < labels.size(); i++) {
             metricBuilder.addLabel(Metrics.LabelPair.newBuilder()
-                    .setName(labels.getName(i))
+                    .setName(labels.getPrometheusName(i))
                     .setValue(labels.getValue(i))
                     .build());
         }
@@ -344,7 +345,7 @@ private void addLabels(Metrics.Metric.Builder metricBuilder, Labels labels) {
     private void addLabels(Metrics.Exemplar.Builder metricBuilder, Labels labels) {
         for (int i = 0; i < labels.size(); i++) {
             metricBuilder.addLabel(Metrics.LabelPair.newBuilder()
-                    .setName(labels.getName(i))
+                    .setName(labels.getPrometheusName(i))
                     .setValue(labels.getValue(i))
                     .build());
         }
diff --git a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusTextFormatWriter.java b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusTextFormatWriter.java
index a4499dd9d..bc187a886 100644
--- a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusTextFormatWriter.java
+++ b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/PrometheusTextFormatWriter.java
@@ -26,6 +26,7 @@
 import static io.prometheus.metrics.expositionformats.TextFormatUtil.writeLabels;
 import static io.prometheus.metrics.expositionformats.TextFormatUtil.writeLong;
 import static io.prometheus.metrics.expositionformats.TextFormatUtil.writeTimestamp;
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
 
 /**
  * Write the Prometheus text format. This is the default if you view a Prometheus endpoint with your Web browser.
@@ -102,7 +103,7 @@ public void writeCreated(OutputStreamWriter writer, MetricSnapshot snapshot) thr
                         writeMetadata(writer, "_created", "gauge", metadata);
                         metadataWritten = true;
                     }
-                    writeNameAndLabels(writer, metadata.getName(), "_created", data.getLabels());
+                    writeNameAndLabels(writer, metadata.getPrometheusName(), "_created", data.getLabels());
                     writeTimestamp(writer, data.getCreatedTimestampMillis());
                     writeScrapeTimestampAndNewline(writer, data);
                 }
@@ -115,7 +116,7 @@ private void writeCounter(OutputStreamWriter writer, CounterSnapshot snapshot) t
             MetricMetadata metadata = snapshot.getMetadata();
             writeMetadata(writer, "_total", "counter", metadata);
             for (CounterSnapshot.CounterDataPointSnapshot data : snapshot.getData()) {
-                writeNameAndLabels(writer, metadata.getName(), "_total", data.getLabels());
+                writeNameAndLabels(writer, metadata.getPrometheusName(), "_total", data.getLabels());
                 writeDouble(writer, data.getValue());
                 writeScrapeTimestampAndNewline(writer, data);
             }
@@ -126,7 +127,7 @@ private void writeGauge(OutputStreamWriter writer, GaugeSnapshot snapshot) throw
         MetricMetadata metadata = snapshot.getMetadata();
         writeMetadata(writer, "", "gauge", metadata);
         for (GaugeSnapshot.GaugeDataPointSnapshot data : snapshot.getData()) {
-            writeNameAndLabels(writer, metadata.getName(), null, data.getLabels());
+            writeNameAndLabels(writer, metadata.getPrometheusName(), null, data.getLabels());
             writeDouble(writer, data.getValue());
             writeScrapeTimestampAndNewline(writer, data);
         }
@@ -140,18 +141,18 @@ private void writeHistogram(OutputStreamWriter writer, HistogramSnapshot snapsho
             long cumulativeCount = 0;
             for (int i = 0; i < buckets.size(); i++) {
                 cumulativeCount += buckets.getCount(i);
-                writeNameAndLabels(writer, metadata.getName(), "_bucket", data.getLabels(), "le", buckets.getUpperBound(i));
+                writeNameAndLabels(writer, metadata.getPrometheusName(), "_bucket", data.getLabels(), "le", buckets.getUpperBound(i));
                 writeLong(writer, cumulativeCount);
                 writeScrapeTimestampAndNewline(writer, data);
             }
             if (!snapshot.isGaugeHistogram()) {
                 if (data.hasCount()) {
-                    writeNameAndLabels(writer, metadata.getName(), "_count", data.getLabels());
+                    writeNameAndLabels(writer, metadata.getPrometheusName(), "_count", data.getLabels());
                     writeLong(writer, data.getCount());
                     writeScrapeTimestampAndNewline(writer, data);
                 }
                 if (data.hasSum()) {
-                    writeNameAndLabels(writer, metadata.getName(), "_sum", data.getLabels());
+                    writeNameAndLabels(writer, metadata.getPrometheusName(), "_sum", data.getLabels());
                     writeDouble(writer, data.getSum());
                     writeScrapeTimestampAndNewline(writer, data);
                 }
@@ -183,7 +184,7 @@ private void writeGaugeCountSum(OutputStreamWriter writer, HistogramSnapshot sna
                     writeMetadata(writer, "_gcount", "gauge", metadata);
                     metadataWritten = true;
                 }
-                writeNameAndLabels(writer, metadata.getName(), "_gcount", data.getLabels());
+                writeNameAndLabels(writer, metadata.getPrometheusName(), "_gcount", data.getLabels());
                 writeLong(writer, data.getCount());
                 writeScrapeTimestampAndNewline(writer, data);
             }
@@ -195,7 +196,7 @@ private void writeGaugeCountSum(OutputStreamWriter writer, HistogramSnapshot sna
                     writeMetadata(writer, "_gsum", "gauge", metadata);
                     metadataWritten = true;
                 }
-                writeNameAndLabels(writer, metadata.getName(), "_gsum", data.getLabels());
+                writeNameAndLabels(writer, metadata.getPrometheusName(), "_gsum", data.getLabels());
                 writeDouble(writer, data.getSum());
                 writeScrapeTimestampAndNewline(writer, data);
             }
@@ -214,17 +215,17 @@ private void writeSummary(OutputStreamWriter writer, SummarySnapshot snapshot) t
                 metadataWritten = true;
             }
             for (Quantile quantile : data.getQuantiles()) {
-                writeNameAndLabels(writer, metadata.getName(), null, data.getLabels(), "quantile", quantile.getQuantile());
+                writeNameAndLabels(writer, metadata.getPrometheusName(), null, data.getLabels(), "quantile", quantile.getQuantile());
                 writeDouble(writer, quantile.getValue());
                 writeScrapeTimestampAndNewline(writer, data);
             }
             if (data.hasCount()) {
-                writeNameAndLabels(writer, metadata.getName(), "_count", data.getLabels());
+                writeNameAndLabels(writer, metadata.getPrometheusName(), "_count", data.getLabels());
                 writeLong(writer, data.getCount());
                 writeScrapeTimestampAndNewline(writer, data);
             }
             if (data.hasSum()) {
-                writeNameAndLabels(writer, metadata.getName(), "_sum", data.getLabels());
+                writeNameAndLabels(writer, metadata.getPrometheusName(), "_sum", data.getLabels());
                 writeDouble(writer, data.getSum());
                 writeScrapeTimestampAndNewline(writer, data);
             }
@@ -235,7 +236,7 @@ private void writeInfo(OutputStreamWriter writer, InfoSnapshot snapshot) throws
         MetricMetadata metadata = snapshot.getMetadata();
         writeMetadata(writer, "_info", "gauge", metadata);
         for (InfoSnapshot.InfoDataPointSnapshot data : snapshot.getData()) {
-            writeNameAndLabels(writer, metadata.getName(), "_info", data.getLabels());
+            writeNameAndLabels(writer, metadata.getPrometheusName(), "_info", data.getLabels());
             writer.write("1");
             writeScrapeTimestampAndNewline(writer, data);
         }
@@ -246,13 +247,13 @@ private void writeStateSet(OutputStreamWriter writer, StateSetSnapshot snapshot)
         writeMetadata(writer, "", "gauge", metadata);
         for (StateSetSnapshot.StateSetDataPointSnapshot data : snapshot.getData()) {
             for (int i = 0; i < data.size(); i++) {
-                writer.write(metadata.getName());
+                writer.write(metadata.getPrometheusName());
                 writer.write('{');
                 for (int j = 0; j < data.getLabels().size(); j++) {
                     if (j > 0) {
                         writer.write(",");
                     }
-                    writer.write(data.getLabels().getName(j));
+                    writer.write(data.getLabels().getPrometheusName(j));
                     writer.write("=\"");
                     writeEscapedLabelValue(writer, data.getLabels().getValue(j));
                     writer.write("\"");
@@ -260,7 +261,7 @@ private void writeStateSet(OutputStreamWriter writer, StateSetSnapshot snapshot)
                 if (!data.getLabels().isEmpty()) {
                     writer.write(",");
                 }
-                writer.write(metadata.getName());
+                writer.write(metadata.getPrometheusName());
                 writer.write("=\"");
                 writeEscapedLabelValue(writer, data.getName(i));
                 writer.write("\"} ");
@@ -278,7 +279,7 @@ private void writeUnknown(OutputStreamWriter writer, UnknownSnapshot snapshot) t
         MetricMetadata metadata = snapshot.getMetadata();
         writeMetadata(writer, "", "untyped", metadata);
         for (UnknownSnapshot.UnknownDataPointSnapshot data : snapshot.getData()) {
-            writeNameAndLabels(writer, metadata.getName(), null, data.getLabels());
+            writeNameAndLabels(writer, metadata.getPrometheusName(), null, data.getLabels());
             writeDouble(writer, data.getValue());
             writeScrapeTimestampAndNewline(writer, data);
         }
@@ -303,7 +304,7 @@ private void writeNameAndLabels(OutputStreamWriter writer, String name, String s
     private void writeMetadata(OutputStreamWriter writer, String suffix, String typeString, MetricMetadata metadata) throws IOException {
         if (metadata.getHelp() != null && !metadata.getHelp().isEmpty()) {
             writer.write("# HELP ");
-            writer.write(metadata.getName());
+            writer.write(metadata.getPrometheusName());
             if (suffix != null) {
                 writer.write(suffix);
             }
@@ -312,7 +313,7 @@ private void writeMetadata(OutputStreamWriter writer, String suffix, String type
             writer.write('\n');
         }
         writer.write("# TYPE ");
-        writer.write(metadata.getName());
+        writer.write(metadata.getPrometheusName());
         if (suffix != null) {
             writer.write(suffix);
         }
diff --git a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/TextFormatUtil.java b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/TextFormatUtil.java
index 5bb15c312..423fa6692 100644
--- a/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/TextFormatUtil.java
+++ b/prometheus-metrics-exposition-formats/src/main/java/io/prometheus/metrics/expositionformats/TextFormatUtil.java
@@ -6,6 +6,8 @@
 import java.io.OutputStreamWriter;
 import java.io.Writer;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
+
 public class TextFormatUtil {
 
     static void writeLong(OutputStreamWriter writer, long value) throws IOException {
@@ -61,7 +63,7 @@ static void writeLabels(OutputStreamWriter writer, Labels labels, String additio
             if (i > 0) {
                 writer.write(",");
             }
-            writer.write(labels.getName(i));
+            writer.write(labels.getPrometheusName(i));
             writer.write("=\"");
             writeEscapedLabelValue(writer, labels.getValue(i));
             writer.write("\"");
diff --git a/prometheus-metrics-exposition-formats/src/test/java/io/prometheus/metrics/expositionformats/ExpositionFormatsTest.java b/prometheus-metrics-exposition-formats/src/test/java/io/prometheus/metrics/expositionformats/ExpositionFormatsTest.java
index 233953e00..7c9e714df 100644
--- a/prometheus-metrics-exposition-formats/src/test/java/io/prometheus/metrics/expositionformats/ExpositionFormatsTest.java
+++ b/prometheus-metrics-exposition-formats/src/test/java/io/prometheus/metrics/expositionformats/ExpositionFormatsTest.java
@@ -23,6 +23,7 @@
 import io.prometheus.metrics.model.snapshots.UnknownSnapshot;
 import io.prometheus.metrics.model.snapshots.UnknownSnapshot.UnknownDataPointSnapshot;
 import org.junit.Assert;
+import org.junit.Ignore;
 import org.junit.Test;
 
 import java.io.ByteArrayOutputStream;
@@ -32,6 +33,7 @@ public class ExpositionFormatsTest {
 
     private final String exemplar1String = "{env=\"prod\",span_id=\"12345\",trace_id=\"abcde\"} 1.7 1672850685.829";
     private final String exemplar2String = "{env=\"dev\",span_id=\"23456\",trace_id=\"bcdef\"} 2.4 1672850685.830";
+    private final String exemplarWithDotsString = "{some_exemplar_key=\"some value\"} 3.0 1690298864.383";
 
     private final String exemplar1protoString = "exemplar { " +
             "label { name: \"env\" value: \"prod\" } " +
@@ -47,6 +49,11 @@ public class ExpositionFormatsTest {
             "value: 2.4 " +
             "timestamp { seconds: 1672850685 nanos: 830000000 } }";
 
+    private final String exemplarWithDotsProtoString = "exemplar { " +
+            "label { name: \"some_exemplar_key\" value: \"some value\" } " +
+            "value: 3.0 " +
+            "timestamp { seconds: 1690298864 nanos: 383000000 } }";
+
     private final String createdTimestamp1s = "1672850385.800";
     private final long createdTimestamp1 = (long) (1000 * Double.parseDouble(createdTimestamp1s));
     private final String createdTimestamp2s = "1672850285.000";
@@ -72,6 +79,12 @@ public class ExpositionFormatsTest {
             .withTimestampMillis(1672850685830L)
             .build();
 
+    private final Exemplar exemplarWithDots = Exemplar.newBuilder()
+            .withLabels(Labels.of("some.exemplar.key", "some value"))
+            .withValue(3.0)
+            .withTimestampMillis(1690298864383L)
+            .build();
+
     @Test
     public void testCounterComplete() throws IOException {
         String openMetricsText = "" +
@@ -183,6 +196,42 @@ public void testCounterMinimal() throws IOException {
         assertPrometheusProtobuf(prometheusProtobuf, counter);
     }
 
+    @Test
+    public void testCounterWithDots() throws IOException {
+        String openMetricsText = "" +
+                "# TYPE my_request_count counter\n" +
+                "my_request_count_total{http_path=\"/hello\"} 3.0 # " + exemplarWithDotsString + "\n" +
+                "# EOF\n";
+        String prometheusText = "" +
+                "# TYPE my_request_count_total counter\n" +
+                "my_request_count_total{http_path=\"/hello\"} 3.0\n";
+        String prometheusProtobuf = "" +
+                //@formatter:off
+                "name: \"my_request_count_total\" " +
+                "type: COUNTER " +
+                "metric { " +
+                    "label { name: \"http_path\" value: \"/hello\" } " +
+                    "counter { " +
+                        "value: 3.0 " + exemplarWithDotsProtoString + " " +
+                    "} " +
+                "}";
+                //@formatter:on
+
+        CounterSnapshot counter = CounterSnapshot.newBuilder()
+                .withName("my.request.count")
+                .addDataPoint(CounterDataPointSnapshot.newBuilder()
+                        .withValue(3.0)
+                        .withLabels(Labels.newBuilder()
+                                .addLabel("http.path", "/hello")
+                                .build())
+                        .withExemplar(exemplarWithDots)
+                        .build())
+                .build();
+        assertOpenMetricsText(openMetricsText, counter);
+        assertPrometheusText(prometheusText, counter);
+        assertPrometheusProtobuf(prometheusProtobuf, counter);
+    }
+
     @Test
     public void testGaugeComplete() throws IOException {
         String openMetricsText = "" +
@@ -264,6 +313,48 @@ public void testGaugeMinimal() throws IOException {
         assertPrometheusProtobuf(prometheusProtobuf, gauge);
     }
 
+    @Test
+    public void testGaugeWithDots() throws IOException {
+        String openMetricsText = "" +
+                "# TYPE my_temperature_celsius gauge\n" +
+                "# UNIT my_temperature_celsius celsius\n" +
+                "# HELP my_temperature_celsius Temperature\n" +
+                "my_temperature_celsius{location_id=\"data-center-1\"} 23.0 # " + exemplarWithDotsString + "\n" +
+                "# EOF\n";
+        String prometheusText = "" +
+                "# HELP my_temperature_celsius Temperature\n" +
+                "# TYPE my_temperature_celsius gauge\n" +
+                "my_temperature_celsius{location_id=\"data-center-1\"} 23.0\n";
+        String prometheusProtobuf = "" +
+                //@formatter:off
+                "name: \"my_temperature_celsius\" " +
+                "help: \"Temperature\" " +
+                "type: GAUGE " +
+                "metric { " +
+                    "label { name: \"location_id\" value: \"data-center-1\" } " +
+                    "gauge { " +
+                        "value: 23.0 " +
+                    "} " +
+                "}";
+                //@formatter:on
+
+        GaugeSnapshot gauge = GaugeSnapshot.newBuilder()
+                .withName("my.temperature.celsius")
+                .withHelp("Temperature")
+                .withUnit(Unit.CELSIUS)
+                .addDataPoint(GaugeDataPointSnapshot.newBuilder()
+                        .withValue(23.0)
+                        .withLabels(Labels.newBuilder()
+                                .addLabel("location.id", "data-center-1")
+                                .build())
+                        .withExemplar(exemplarWithDots)
+                        .build())
+                .build();
+        assertOpenMetricsText(openMetricsText, gauge);
+        assertPrometheusText(prometheusText, gauge);
+        assertPrometheusProtobuf(prometheusProtobuf, gauge);
+    }
+
     @Test
     public void testSummaryComplete() throws IOException {
         String openMetricsText = "" +
@@ -596,6 +687,49 @@ public void testSummaryEmptyAndNonEmpty() throws IOException {
         assertPrometheusProtobuf(prometheusProtobuf, summary);
     }
 
+    @Test
+    public void testSummaryWithDots() throws IOException {
+        String openMetricsText = "" +
+                "# TYPE my_request_duration_seconds summary\n" +
+                "# UNIT my_request_duration_seconds seconds\n" +
+                "# HELP my_request_duration_seconds Request duration in seconds\n" +
+                "my_request_duration_seconds_count{http_path=\"/hello\"} 1 # " + exemplarWithDotsString + "\n" +
+                "my_request_duration_seconds_sum{http_path=\"/hello\"} 0.03 # " + exemplarWithDotsString + "\n" +
+                "# EOF\n";
+        String prometheusText = "" +
+                "# HELP my_request_duration_seconds Request duration in seconds\n" +
+                "# TYPE my_request_duration_seconds summary\n" +
+                "my_request_duration_seconds_count{http_path=\"/hello\"} 1\n" +
+                "my_request_duration_seconds_sum{http_path=\"/hello\"} 0.03\n";
+        String prometheusProtobuf = "" +
+                //@formatter:off
+                "name: \"my_request_duration_seconds\" " +
+                "help: \"Request duration in seconds\" " +
+                "type: SUMMARY " +
+                "metric { " +
+                    "label { name: \"http_path\" value: \"/hello\" } " +
+                    "summary { sample_count: 1 sample_sum: 0.03 } " +
+                "}";
+                //@formatter:on
+
+        SummarySnapshot summary = SummarySnapshot.newBuilder()
+                .withName("my.request.duration.seconds")
+                .withHelp("Request duration in seconds")
+                .withUnit(Unit.SECONDS)
+                .addDataPoint(SummaryDataPointSnapshot.newBuilder()
+                        .withCount(1)
+                        .withSum(0.03)
+                        .withLabels(Labels.newBuilder()
+                                .addLabel("http.path", "/hello")
+                                .build())
+                        .withExemplars(Exemplars.of(exemplarWithDots))
+                        .build())
+                .build();
+        assertOpenMetricsText(openMetricsText, summary);
+        assertPrometheusText(prometheusText, summary);
+        assertPrometheusProtobuf(prometheusProtobuf, summary);
+    }
+
     @Test
     public void testClassicHistogramComplete() throws Exception {
         String openMetricsText = "" +
@@ -1047,6 +1181,57 @@ public void testClassicGaugeHistogramCountAndSum() throws IOException {
         assertPrometheusProtobuf(prometheusProtobuf, gaugeHistogram);
     }
 
+    @Test
+    public void testClassicHistogramWithDots() throws IOException {
+        String openMetricsText = "" +
+                "# TYPE my_request_duration_seconds histogram\n" +
+                "# UNIT my_request_duration_seconds seconds\n" +
+                "# HELP my_request_duration_seconds Request duration in seconds\n" +
+                "my_request_duration_seconds_bucket{http_path=\"/hello\",le=\"+Inf\"} 130 # " + exemplarWithDotsString + "\n" +
+                "my_request_duration_seconds_count{http_path=\"/hello\"} 130\n" +
+                "my_request_duration_seconds_sum{http_path=\"/hello\"} 0.01\n" +
+                "# EOF\n";
+        String prometheusText = "" +
+                "# HELP my_request_duration_seconds Request duration in seconds\n" +
+                "# TYPE my_request_duration_seconds histogram\n" +
+                "my_request_duration_seconds_bucket{http_path=\"/hello\",le=\"+Inf\"} 130\n" +
+                "my_request_duration_seconds_count{http_path=\"/hello\"} 130\n" +
+                "my_request_duration_seconds_sum{http_path=\"/hello\"} 0.01\n";
+        String prometheusProtobuf = "" +
+                //@formatter:off
+                "name: \"my_request_duration_seconds\" " +
+                "help: \"Request duration in seconds\" " +
+                "type: HISTOGRAM " +
+                "metric { " +
+                    "label { name: \"http_path\" value: \"/hello\" } " +
+                    "histogram { " +
+                        "sample_count: 130 " +
+                        "sample_sum: 0.01 " +
+                        "bucket { cumulative_count: 130 upper_bound: Infinity " + exemplarWithDotsProtoString + " } " +
+                    "} " +
+                "}";
+                //@formatter:on
+
+        HistogramSnapshot histogram = HistogramSnapshot.newBuilder()
+                .withName("my.request.duration.seconds")
+                .withHelp("Request duration in seconds")
+                .withUnit(Unit.SECONDS)
+                .addDataPoint(HistogramSnapshot.HistogramDataPointSnapshot.newBuilder()
+                        .withSum(0.01)
+                        .withLabels(Labels.newBuilder()
+                                .addLabel("http.path", "/hello")
+                                .build())
+                        .withClassicHistogramBuckets(ClassicHistogramBuckets.newBuilder()
+                                .addBucket(Double.POSITIVE_INFINITY, 130)
+                                .build())
+                        .withExemplars(Exemplars.of(exemplarWithDots))
+                        .build())
+                .build();
+        assertOpenMetricsText(openMetricsText, histogram);
+        assertPrometheusText(prometheusText, histogram);
+        assertPrometheusProtobuf(prometheusProtobuf, histogram);
+    }
+
     @Test
     public void testNativeHistogramComplete() throws IOException {
         String openMetricsText = "" +
@@ -1244,6 +1429,64 @@ public void testNativeHistogramMinimal() throws IOException {
         assertPrometheusProtobuf(prometheusProtobuf, nativeHistogram);
     }
 
+    @Test
+    public void testNativeHistogramWithDots() throws IOException {
+        String openMetricsText = "" +
+                "# TYPE my_request_duration_seconds histogram\n" +
+                "# UNIT my_request_duration_seconds seconds\n" +
+                "# HELP my_request_duration_seconds Request duration in seconds\n" +
+                "my_request_duration_seconds_bucket{http_path=\"/hello\",le=\"+Inf\"} 4 # " + exemplarWithDotsString + "\n" +
+                "my_request_duration_seconds_count{http_path=\"/hello\"} 4\n" +
+                "my_request_duration_seconds_sum{http_path=\"/hello\"} 3.2\n" +
+                "# EOF\n";
+        String prometheusText = "" +
+                "# HELP my_request_duration_seconds Request duration in seconds\n" +
+                "# TYPE my_request_duration_seconds histogram\n" +
+                "my_request_duration_seconds_bucket{http_path=\"/hello\",le=\"+Inf\"} 4\n" +
+                "my_request_duration_seconds_count{http_path=\"/hello\"} 4\n" +
+                "my_request_duration_seconds_sum{http_path=\"/hello\"} 3.2\n";
+        String prometheusProtobuf = "" +
+                //@formatter:off
+                "name: \"my_request_duration_seconds\" " +
+                "help: \"Request duration in seconds\" " +
+                "type: HISTOGRAM " +
+                "metric { " +
+                    "label { name: \"http_path\" value: \"/hello\" } " +
+                    "histogram { " +
+                        "sample_count: 4 " +
+                        "sample_sum: 3.2 " +
+                        "bucket { cumulative_count: 4 upper_bound: Infinity " + exemplarWithDotsProtoString + " } " +
+                        "schema: 5 " +
+                        "zero_threshold: 0.0 " +
+                        "zero_count: 1 " +
+                        "positive_span { offset: 2 length: 1 } " +
+                        "positive_delta: 3 " +
+                    "} " +
+                "}";
+                //@formatter:on
+
+        HistogramSnapshot histogram = HistogramSnapshot.newBuilder()
+                .withName("my.request.duration.seconds")
+                .withHelp("Request duration in seconds")
+                .withUnit(Unit.SECONDS)
+                .addDataPoint(HistogramSnapshot.HistogramDataPointSnapshot.newBuilder()
+                        .withLabels(Labels.newBuilder()
+                                .addLabel("http.path", "/hello")
+                                .build())
+                        .withSum(3.2)
+                        .withNativeSchema(5)
+                        .withNativeZeroCount(1)
+                        .withNativeBucketsForPositiveValues(NativeHistogramBuckets.newBuilder()
+                                .addBucket(2, 3)
+                                .build()
+                        )
+                        .withExemplars(Exemplars.of(exemplarWithDots))
+                        .build())
+                .build();
+        assertOpenMetricsText(openMetricsText, histogram);
+        assertPrometheusText(prometheusText, histogram);
+        assertPrometheusProtobuf(prometheusProtobuf, histogram);
+    }
     // TODO: Gauge Native Histogram
 
     @Test
@@ -1270,6 +1513,39 @@ public void testInfo() throws IOException {
         assertPrometheusTextWithoutCreated(prometheus, info);
     }
 
+    @Test
+    public void testInfoWithDots() throws IOException {
+        String openMetricsText = "" +
+                "# TYPE jvm_status info\n" +
+                "# HELP jvm_status JVM status info\n" +
+                "jvm_status_info{jvm_version=\"1.2.3\"} 1\n" +
+                "# EOF\n";
+        String prometheusText = "" +
+                "# HELP jvm_status_info JVM status info\n" +
+                "# TYPE jvm_status_info gauge\n" +
+                "jvm_status_info{jvm_version=\"1.2.3\"} 1\n";
+        String prometheusProtobuf = "" +
+                //@formatter:off
+                "name: \"jvm_status_info\" " +
+                "help: \"JVM status info\" " +
+                "type: GAUGE " +
+                "metric { " + "" +
+                    "label { name: \"jvm_version\" value: \"1.2.3\" } " +
+                    "gauge { value: 1.0 } " +
+                "}";
+                //@formatter:on
+        InfoSnapshot info = InfoSnapshot.newBuilder()
+                .withName("jvm.status")
+                .withHelp("JVM status info")
+                .addDataPoint(InfoSnapshot.InfoDataPointSnapshot.newBuilder()
+                        .withLabels(Labels.of("jvm.version", "1.2.3"))
+                        .build())
+                .build();
+        assertOpenMetricsText(openMetricsText, info);
+        assertPrometheusText(prometheusText, info);
+        assertPrometheusProtobuf(prometheusProtobuf, info);
+    }
+
     @Test
     public void testStateSetComplete() throws IOException {
         String openMetrics = "" +
@@ -1333,6 +1609,48 @@ public void testStateSetMinimal() throws IOException {
         assertPrometheusTextWithoutCreated(prometheus, stateSet);
     }
 
+    @Test
+    public void testStateSetWithDots() throws IOException {
+        String openMetricsText = "" +
+                "# TYPE my_application_state stateset\n" +
+                "# HELP my_application_state My application state\n" +
+                "my_application_state{data_center=\"us east\",my_application_state=\"feature.enabled\"} 1\n" +
+                "my_application_state{data_center=\"us east\",my_application_state=\"is.alpha.version\"} 0\n" +
+                "# EOF\n";
+        String prometheusText = "" +
+                "# HELP my_application_state My application state\n" +
+                "# TYPE my_application_state gauge\n" +
+                "my_application_state{data_center=\"us east\",my_application_state=\"feature.enabled\"} 1\n" +
+                "my_application_state{data_center=\"us east\",my_application_state=\"is.alpha.version\"} 0\n";
+        String prometheusProtobuf = "" +
+                //@formatter:off
+                "name: \"my_application_state\" " +
+                "help: \"My application state\" " +
+                "type: GAUGE " +
+                "metric { " +
+                    "label { name: \"data_center\" value: \"us east\" } " +
+                    "label { name: \"my_application_state\" value: \"feature.enabled\" } " +
+                    "gauge { value: 1.0 } " +
+                "} metric { " +
+                    "label { name: \"data_center\" value: \"us east\" } " +
+                    "label { name: \"my_application_state\" value: \"is.alpha.version\" } " +
+                    "gauge { value: 0.0 } " +
+                "}";
+                //@formatter:on
+        StateSetSnapshot stateSet = StateSetSnapshot.newBuilder()
+                .withName("my.application.state")
+                .withHelp("My application state")
+                .addDataPoint(StateSetSnapshot.StateSetDataPointSnapshot.newBuilder()
+                        .withLabels(Labels.of("data.center", "us east"))
+                        .addState("feature.enabled", true)
+                        .addState("is.alpha.version", false)
+                        .build())
+                .build();
+        assertOpenMetricsText(openMetricsText, stateSet);
+        assertPrometheusText(prometheusText, stateSet);
+        assertPrometheusProtobuf(prometheusProtobuf, stateSet);
+    }
+
     @Test
     public void testUnknownComplete() throws IOException {
         String openMetrics = "" +
@@ -1391,6 +1709,43 @@ public void testUnknownMinimal() throws IOException {
         assertPrometheusTextWithoutCreated(prometheus, unknown);
     }
 
+    @Test
+    public void testUnknownWithDots() throws IOException {
+        String openMetrics = "" +
+                "# TYPE some_unknown_metric unknown\n" +
+                "# UNIT some_unknown_metric bytes\n" +
+                "# HELP some_unknown_metric help message\n" +
+                "some_unknown_metric{test_env=\"7\"} 0.7 # " + exemplarWithDotsString + "\n" +
+                "# EOF\n";
+        String prometheus = "" +
+                "# HELP some_unknown_metric help message\n" +
+                "# TYPE some_unknown_metric untyped\n" +
+                "some_unknown_metric{test_env=\"7\"} 0.7\n";
+        String prometheusProtobuf = "" +
+                //@formatter:off
+                "name: \"some_unknown_metric\" " +
+                "help: \"help message\" " +
+                "type: UNTYPED " +
+                "metric { " +
+                    "label { name: \"test_env\" value: \"7\" } " +
+                    "untyped { value: 0.7 } " +
+                "}";
+                //@formatter:on
+        UnknownSnapshot unknown = UnknownSnapshot.newBuilder()
+                .withName("some.unknown.metric")
+                .withHelp("help message")
+                .withUnit(Unit.BYTES)
+                .addDataPoint(UnknownDataPointSnapshot.newBuilder()
+                        .withValue(0.7)
+                        .withLabels(Labels.of("test.env", "7"))
+                        .withExemplar(exemplarWithDots)
+                        .build())
+                .build();
+        assertOpenMetricsText(openMetrics, unknown);
+        assertPrometheusText(prometheus, unknown);
+        assertPrometheusProtobuf(prometheusProtobuf, unknown);
+    }
+
     @Test
     public void testHelpEscape() throws IOException {
         String openMetrics = "" +
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java
index b0fba2db1..349ebda60 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java
@@ -1,11 +1,11 @@
 package io.prometheus.metrics.model.registry;
 
 import io.prometheus.metrics.model.snapshots.MetricSnapshot;
-import io.prometheus.metrics.model.snapshots.MetricSnapshots;
 
-import java.util.List;
 import java.util.function.Predicate;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
+
 /**
  * To be registered with the Prometheus collector registry.
  * See <i>Overall Structure</i> on
@@ -26,7 +26,7 @@ public interface Collector {
      */
     default MetricSnapshot collect(Predicate<String> includedNames) {
         MetricSnapshot result = collect();
-        if (includedNames.test(result.getMetadata().getName())) {
+        if (includedNames.test(result.getMetadata().getPrometheusName())) {
             return result;
         } else {
             return null;
@@ -36,7 +36,7 @@ default MetricSnapshot collect(Predicate<String> includedNames) {
     /**
      * Override this and return {@code null} if a collector does not have a constant name (name may change between scrapes).
      */
-    default String getName() {
-        return collect().getMetadata().getName();
+    default String getPrometheusName() {
+        return collect().getMetadata().getPrometheusName();
     }
 }
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java
index 3fd56e493..8e5aff15f 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java
@@ -7,6 +7,8 @@
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
+
 /**
  * Like {@link Collector}, but collecting multiple Snapshots at once.
  */
@@ -27,7 +29,7 @@ default MetricSnapshots collect(Predicate<String> includedNames) {
         MetricSnapshots allSnapshots = collect();
         MetricSnapshots.Builder result = MetricSnapshots.newBuilder();
         for (MetricSnapshot snapshot : allSnapshots) {
-            if (includedNames.test(snapshot.getMetadata().getName())) {
+            if (includedNames.test(snapshot.getMetadata().getPrometheusName())) {
                 result.addMetricSnapshot(snapshot);
             }
         }
@@ -38,7 +40,7 @@ default MetricSnapshots collect(Predicate<String> includedNames) {
      * Override this and return an empty list if the MultiCollector does not return a constant list of names
      * (names may be added / removed between scrapes).
      */
-    default List<String> getNames() {
-        return collect().stream().map(snapshot -> snapshot.getMetadata().getName()).collect(Collectors.toList());
+    default List<String> getPrometheusNames() {
+        return collect().stream().map(snapshot -> snapshot.getMetadata().getPrometheusName()).collect(Collectors.toList());
     }
 }
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/PrometheusRegistry.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/PrometheusRegistry.java
index 858a1b37d..373d32a89 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/PrometheusRegistry.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/PrometheusRegistry.java
@@ -9,26 +9,30 @@
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.function.Predicate;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
+
 public class PrometheusRegistry {
 
     public static final PrometheusRegistry defaultRegistry = new PrometheusRegistry();
 
-    private final Set<String> names = ConcurrentHashMap.newKeySet();
+    private final Set<String> prometheusNames = ConcurrentHashMap.newKeySet();
     private final List<Collector> collectors = new CopyOnWriteArrayList<>();
     private final List<MultiCollector> multiCollectors = new CopyOnWriteArrayList<>();
 
     public void register(Collector collector) {
-        String name = collector.getName();
-        if (!names.add(name)) {
-            throw new IllegalStateException("Can't register " + name + " because that name is already registered.");
+        String prometheusName = collector.getPrometheusName();
+        if (prometheusName != null) {
+            if (!prometheusNames.add(prometheusName)) {
+                throw new IllegalStateException("Can't register " + prometheusName + " because a metric with that name is already registered.");
+            }
         }
         collectors.add(collector);
     }
 
     public void register(MultiCollector collector) {
-        for (String name : collector.getNames()) {
-            if (!names.add(name)) {
-                throw new IllegalStateException("Can't register " + name + " because that name is already registered.");
+        for (String prometheusName : collector.getPrometheusNames()) {
+            if (!prometheusNames.add(prometheusName)) {
+                throw new IllegalStateException("Can't register " + prometheusName + " because that name is already registered.");
             }
         }
         multiCollectors.add(collector);
@@ -36,23 +40,32 @@ public void register(MultiCollector collector) {
 
     public void unregister(Collector collector) {
         collectors.remove(collector);
-        names.remove(collector.getName());
+        prometheusNames.remove(collector.getPrometheusName());
     }
 
     public void unregister(MultiCollector collector) {
         multiCollectors.remove(collector);
-        for (String name : collector.getNames()) {
-            names.remove(name);
+        for (String prometheusName : collector.getPrometheusNames()) {
+            prometheusNames.remove(prometheusName(prometheusName));
         }
     }
 
     public MetricSnapshots scrape() {
         MetricSnapshots.Builder result = MetricSnapshots.newBuilder();
         for (Collector collector : collectors) {
-            result.addMetricSnapshot(collector.collect());
+            MetricSnapshot snapshot = collector.collect();
+            if (snapshot != null) {
+                if (result.containsMetricName(snapshot.getMetadata().getName())) {
+                    throw new IllegalStateException(snapshot.getMetadata().getPrometheusName() + ": duplicate metric name.");
+                }
+                result.addMetricSnapshot(snapshot);
+            }
         }
         for (MultiCollector collector : multiCollectors) {
             for (MetricSnapshot snapshot : collector.collect()) {
+                if (result.containsMetricName(snapshot.getMetadata().getName())) {
+                    throw new IllegalStateException(snapshot.getMetadata().getPrometheusName() + ": duplicate metric name.");
+                }
                 result.addMetricSnapshot(snapshot);
             }
         }
@@ -65,8 +78,8 @@ public MetricSnapshots scrape(Predicate<String> includedNames) {
         }
         MetricSnapshots.Builder result = MetricSnapshots.newBuilder();
         for (Collector collector : collectors) {
-            String name = collector.getName();
-            if (name == null || includedNames.test(name)) {
+            String prometheusName = collector.getPrometheusName();
+            if (prometheusName == null || includedNames.test(prometheusName)) {
                 MetricSnapshot snapshot = collector.collect(includedNames);
                 if (snapshot != null) {
                     result.addMetricSnapshot(snapshot);
@@ -74,10 +87,10 @@ public MetricSnapshots scrape(Predicate<String> includedNames) {
             }
         }
         for (MultiCollector collector : multiCollectors) {
-            List<String> names = collector.getNames();
+            List<String> prometheusNames = collector.getPrometheusNames();
             boolean excluded = true; // the multi-collector is excluded unless at least one name matches
-            for (String name : names) {
-                if (includedNames.test(name)) {
+            for (String prometheusName : prometheusNames) {
+                if (includedNames.test(prometheusName)) {
                     excluded = false;
                     break;
                 }
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/InfoSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/InfoSnapshot.java
index b49e0d121..dac311004 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/InfoSnapshot.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/InfoSnapshot.java
@@ -20,9 +20,6 @@ public final class InfoSnapshot extends MetricSnapshot {
      */
     public InfoSnapshot(MetricMetadata metadata, Collection<InfoDataPointSnapshot> data) {
         super(metadata, data);
-        if (metadata.getName().endsWith("_info")) {
-            throw new IllegalArgumentException("The name of an info snapshot must not include the _info suffix");
-        }
         if (metadata.hasUnit()) {
             throw new IllegalArgumentException("An Info metric cannot have a unit.");
         }
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/Labels.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/Labels.java
index 8f9d36ea4..60b1b58be 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/Labels.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/Labels.java
@@ -5,23 +5,37 @@
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
-import java.util.regex.Pattern;
 import java.util.stream.Stream;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.isValidLabelName;
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
+
 /**
  * Immutable set of name/value pairs, sorted by name.
  */
 public class Labels implements Comparable<Labels>, Iterable<Label> {
 
-    public static final Labels EMPTY = new Labels(new String[]{}, new String[]{});
-    private static final Pattern LABEL_NAME_RE = Pattern.compile("^[a-zA-Z_][a-zA-Z0-9_]*$");
+    public static final Labels EMPTY;
+
+    static {
+        String[] names = new String[]{};
+        String[] values = new String[]{};
+        EMPTY = new Labels(names, names, values);
+    }
 
-    private final String[] names; // sorted
+    // prometheusNames is the same as names, but dots are replaced with underscores.
+    // Labels is sorted by prometheusNames.
+    // If names[i] does not contain a dot, prometheusNames[i] references the same String as names[i]
+    // so that we don't have unnecessary duplicates of strings.
+    // If none of the names contains a dot, then prometheusNames references the same array as names
+    // so that we don't have unnecessary duplicate arrays.
+    private final String[] prometheusNames;
+    private final String[] names;
     private final String[] values;
 
-    private Labels(String[] names, String[] values) {
-        // names and values are already sorted and validated
+    private Labels(String[] names, String[] prometheusNames, String[] values) {
         this.names = names;
+        this.prometheusNames = prometheusNames;
         this.values = values;
     }
 
@@ -35,9 +49,9 @@ public boolean isEmpty() {
      * or you can use the {@link Labels#newBuilder()}.
      *
      * @param keyValuePairs as in {@code {name1, value1, name2, value2}}. Length must be even.
-     *                      {@link #isValidLabelName(String)} must be true for each name.
-     *                      Use {@link #sanitizeLabelName(String)} to convert arbitrary strings to valid
-     *                      label names. Label names must be unique (no duplicate label names).
+     *                      {@link PrometheusNaming#isValidLabelName(String)} must be true for each name.
+     *                      Use {@link PrometheusNaming#sanitizeLabelName(String)} to convert arbitrary strings
+     *                      to valid label names. Label names must be unique (no duplicate label names).
      */
     public static Labels of(String... keyValuePairs) {
         if (keyValuePairs.length % 2 != 0) {
@@ -52,7 +66,23 @@ public static Labels of(String... keyValuePairs) {
             names[i] = keyValuePairs[2 * i];
             values[i] = keyValuePairs[2 * i + 1];
         }
-        return Labels.of(names, values);
+        String[] prometheusNames = makePrometheusNames(names);
+        sortAndValidate(names, prometheusNames, values);
+        return new Labels(names, prometheusNames, values);
+    }
+
+    // package private for testing
+    static String[] makePrometheusNames(String[] names) {
+        String[] prometheusNames = names;
+        for (int i=0; i<names.length; i++) {
+            if (names[i].contains(".")) {
+                if (prometheusNames == names) {
+                    prometheusNames = Arrays.copyOf(names, names.length);
+                }
+                prometheusNames[i] = PrometheusNaming.prometheusName(names[i]);
+            }
+        }
+        return prometheusNames;
     }
 
     /**
@@ -60,10 +90,10 @@ public static Labels of(String... keyValuePairs) {
      * You can either create Labels with one of the static {@code Labels.of(...)} methods,
      * or you can use the {@link Labels#newBuilder()}.
      *
-     * @param names  label names. {@link #isValidLabelName(String)} must be true for each name.
-     *               Use {@link #sanitizeLabelName(String)} to convert arbitrary strings to valid label names.
-     *               Label names must be unique (no duplicate label names).
-     * @param values label values. names.size() must be equal to values.size().
+     * @param names  label names. {@link PrometheusNaming#isValidLabelName(String)} must be true for each name.
+     *               Use {@link PrometheusNaming#sanitizeLabelName(String)} to convert arbitrary strings
+     *               to valid label names. Label names must be unique (no duplicate label names).
+     * @param values label values. {@code names.size()} must be equal to {@code values.size()}.
      */
     public static Labels of(List<String> names, List<String> values) {
         if (names.size() != values.size()) {
@@ -74,8 +104,9 @@ public static Labels of(List<String> names, List<String> values) {
         }
         String[] namesCopy = names.toArray(new String[0]);
         String[] valuesCopy = values.toArray(new String[0]);
-        sortAndValidate(namesCopy, valuesCopy);
-        return new Labels(namesCopy, valuesCopy);
+        String[] prometheusNames = makePrometheusNames(namesCopy);
+        sortAndValidate(namesCopy, prometheusNames, valuesCopy);
+        return new Labels(namesCopy, prometheusNames, valuesCopy);
     }
 
     /**
@@ -83,10 +114,10 @@ public static Labels of(List<String> names, List<String> values) {
      * You can either create Labels with one of the static {@code Labels.of(...)} methods,
      * or you can use the {@link Labels#newBuilder()}.
      *
-     * @param names  label names. {@link #isValidLabelName(String)} must be true for each name.
-     *               Use {@link #sanitizeLabelName(String)} to convert arbitrary strings to valid label names.
-     *               Label names must be unique (no duplicate label names).
-     * @param values label values. names.length must be equal to values.length.
+     * @param names  label names. {@link PrometheusNaming#isValidLabelName(String)} must be true for each name.
+     *               Use {@link PrometheusNaming#sanitizeLabelName(String)} to convert arbitrary strings
+     *               to valid label names. Label names must be unique (no duplicate label names).
+     * @param values label values. {@code names.length} must be equal to {@code values.length}.
      */
     public static Labels of(String[] names, String[] values) {
         if (names.length != values.length) {
@@ -97,15 +128,19 @@ public static Labels of(String[] names, String[] values) {
         }
         String[] namesCopy = Arrays.copyOf(names, names.length);
         String[] valuesCopy = Arrays.copyOf(values, values.length);
-        sortAndValidate(namesCopy, valuesCopy);
-        return new Labels(namesCopy, valuesCopy);
+        String[] prometheusNames = makePrometheusNames(namesCopy);
+        sortAndValidate(namesCopy, prometheusNames, valuesCopy);
+        return new Labels(namesCopy, prometheusNames, valuesCopy);
     }
 
     /**
      * Test if these labels contain a specific label name.
+     * <p>
+     * Dots are treated as underscores, so {@code contains("my.label")} and {@code contains("my_label")} are the same.
      */
     public boolean contains(String labelName) {
-        for (String name : names) {
+        labelName = prometheusName(labelName);
+        for (String name : prometheusNames) {
             if (name.equals(labelName)) {
                 return true;
             }
@@ -113,56 +148,47 @@ public boolean contains(String labelName) {
         return false;
     }
 
-    private static void sortAndValidate(String[] names, String[] values) {
-        sort(names, values);
-        validateNames(names);
+    private static void sortAndValidate(String[] names, String[] prometheusNames, String[] values) {
+        sort(names, prometheusNames, values);
+        validateNames(names, prometheusNames);
     }
 
-    private static void validateNames(String[] names) {
+    private static void validateNames(String[] names, String[] prometheusNames) {
         for (int i = 0; i < names.length; i++) {
             if (!isValidLabelName(names[i])) {
                 throw new IllegalArgumentException("'" + names[i] + "' is an illegal label name");
             }
-            if (i > 0 && names[i - 1].equals(names[i])) {
+            // The arrays are sorted, so duplicates are next to each other
+            if (i > 0 && prometheusNames[i - 1].equals(prometheusNames[i])) {
                 throw new IllegalArgumentException(names[i] + ": duplicate label name");
             }
         }
     }
 
-    private static void sort(String[] names, String[] values) {
-        // bubblesort :)
-        int n = names.length;
+    private static void sort(String[] names, String[] prometheusNames, String[] values) {
+        // bubblesort
+        int n = prometheusNames.length;
         for (int i = 0; i < n - 1; i++) {
             for (int j = 0; j < n - i - 1; j++) {
-                if (names[j].compareTo(names[j + 1]) > 0) {
-                    swap(j, j + 1, names, values);
+                if (prometheusNames[j].compareTo(prometheusNames[j + 1]) > 0) {
+                    swap(j, j + 1, names, prometheusNames, values);
                 }
             }
         }
     }
 
-    private static void swap(int i, int j, String[] names, String[] values) {
+    private static void swap(int i, int j, String[] names, String[] prometheusNames, String[] values) {
         String tmp = names[j];
         names[j] = names[i];
         names[i] = tmp;
         tmp = values[j];
         values[j] = values[i];
         values[i] = tmp;
-    }
-
-    public static boolean isValidLabelName(String name) {
-        return LABEL_NAME_RE.matcher(name).matches() && !name.startsWith("__");
-    }
-
-    /**
-     * Convert arbitrary label names to valid Prometheus label names.
-     */
-    public static String sanitizeLabelName(String labelName) {
-        String result = MetricMetadata.sanitizeMetricName(labelName);
-        while (result.startsWith("__")) {
-            result = result.substring(1);
+        if (prometheusNames != names) {
+            tmp = prometheusNames[j];
+            prometheusNames[j] = prometheusNames[i];
+            prometheusNames[i] = tmp;
         }
-        return result;
     }
 
     @Override
@@ -182,6 +208,15 @@ public String getName(int i) {
         return names[i];
     }
 
+    /**
+     * Like {@link #getName(int)}, but dots are replaced with underscores.
+     * <p>
+     * This is used by Prometheus exposition formats.
+     */
+    public String getPrometheusName(int i) {
+        return prometheusNames[i];
+    }
+
     public String getValue(int i) {
         return values[i];
     }
@@ -191,7 +226,17 @@ public String getValue(int i) {
      * This and other must not contain the same label name.
      */
     public Labels merge(Labels other) {
+        if (this.isEmpty()) {
+            return other;
+        }
+        if (other.isEmpty()) {
+            return this;
+        }
         String[] names = new String[this.names.length + other.names.length];
+        String[] prometheusNames = names;
+        if (this.names != this.prometheusNames || other.names != other.prometheusNames) {
+            prometheusNames = new String[names.length];
+        }
         String[] values = new String[names.length];
         int thisPos = 0;
         int otherPos = 0;
@@ -199,24 +244,36 @@ public Labels merge(Labels other) {
             if (thisPos >= this.names.length) {
                 names[thisPos + otherPos] = other.names[otherPos];
                 values[thisPos + otherPos] = other.values[otherPos];
+                if (prometheusNames != names) {
+                    prometheusNames[thisPos + otherPos] = other.prometheusNames[otherPos];
+                }
                 otherPos++;
             } else if (otherPos >= other.names.length) {
                 names[thisPos + otherPos] = this.names[thisPos];
                 values[thisPos + otherPos] = this.values[thisPos];
+                if (prometheusNames != names) {
+                    prometheusNames[thisPos + otherPos] = this.prometheusNames[thisPos];
+                }
                 thisPos++;
-            } else if (this.names[thisPos].compareTo(other.names[otherPos]) < 0) {
+            } else if (this.prometheusNames[thisPos].compareTo(other.prometheusNames[otherPos]) < 0) {
                 names[thisPos + otherPos] = this.names[thisPos];
                 values[thisPos + otherPos] = this.values[thisPos];
+                if (prometheusNames != names) {
+                    prometheusNames[thisPos + otherPos] = this.prometheusNames[thisPos];
+                }
                 thisPos++;
-            } else if (this.names[thisPos].compareTo(other.names[otherPos]) > 0) {
+            } else if (this.prometheusNames[thisPos].compareTo(other.prometheusNames[otherPos]) > 0) {
                 names[thisPos + otherPos] = other.names[otherPos];
                 values[thisPos + otherPos] = other.values[otherPos];
+                if (prometheusNames != names) {
+                    prometheusNames[thisPos + otherPos] = other.prometheusNames[otherPos];
+                }
                 otherPos++;
             } else {
                 throw new IllegalArgumentException("Duplicate label name: '" + this.names[thisPos] + "'.");
             }
         }
-        return new Labels(names, values);
+        return new Labels(names, prometheusNames, values);
     }
 
     /**
@@ -241,12 +298,13 @@ public Labels merge(String[] names, String[] values) {
         System.arraycopy(this.values, 0, mergedValues, 0, this.values.length);
         System.arraycopy(names, 0, mergedNames, this.names.length, names.length);
         System.arraycopy(values, 0, mergedValues, this.values.length, values.length);
-        sortAndValidate(mergedNames, mergedValues);
-        return new Labels(mergedNames, mergedValues);
+        String[] prometheusNames = makePrometheusNames(mergedNames);
+        sortAndValidate(mergedNames, prometheusNames, mergedValues);
+        return new Labels(mergedNames, prometheusNames, mergedValues);
     }
 
     public boolean hasSameNames(Labels other) {
-        return Arrays.equals(names, other.names);
+        return Arrays.equals(prometheusNames, other.prometheusNames);
     }
 
     public boolean hasSameValues(Labels other) {
@@ -255,7 +313,7 @@ public boolean hasSameValues(Labels other) {
 
     @Override
     public int compareTo(Labels other) {
-        int result = compare(names, other.names);
+        int result = compare(prometheusNames, other.prometheusNames);
         if (result != 0) {
             return result;
         }
@@ -288,6 +346,11 @@ private List<Label> asList() {
         return Collections.unmodifiableList(result);
     }
 
+    /**
+     * This must not be used in Prometheus exposition formats because names may contain dots.
+     * <p>
+     * However, for debugging it's better to show the original names rather than the Prometheus names.
+     */
     @Override
     public String toString() {
         StringBuilder b = new StringBuilder();
@@ -324,18 +387,17 @@ private void appendEscapedLabelValue(StringBuilder b, String value) {
         }
     }
 
-    // as labels are sorted by name, equals is insensitive to the order
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
         Labels labels = (Labels) o;
-        return Arrays.equals(names, labels.names) && Arrays.equals(values, labels.values);
+        return labels.hasSameNames(this) && labels.hasSameValues(this);
     }
 
     @Override
     public int hashCode() {
-        int result = Arrays.hashCode(names);
+        int result = Arrays.hashCode(prometheusNames);
         result = 31 * result + Arrays.hashCode(values);
         return result;
     }
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricMetadata.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricMetadata.java
index c8fd3e1b2..366805ddf 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricMetadata.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricMetadata.java
@@ -1,28 +1,37 @@
 package io.prometheus.metrics.model.snapshots;
 
-import java.util.regex.Pattern;
-
 /**
  * Immutable container for metric metadata: name, help, unit.
  */
 public final class MetricMetadata {
-    private static final Pattern METRIC_NAME_RE = Pattern.compile("^[a-zA-Z_:][a-zA-Z0-9_:]+$");
-    // According to OpenMetrics _count and _sum (and _gcount, _gsum) should also be reserved suffixes.
-    // However, popular instrumentation libraries have many Gauges with a name ending in _count. Examples:
-    // * Micrometer: jvm_buffer_count
-    // * OpenTelemetry: process_runtime_jvm_buffer_count
-    // We allow the _count and _sum suffixes here so that these names are supported, even though this might
-    // conflict if there is a histogram or summary named "jvm_buffer" or "process_runtime_jvm_buffer".
-    private static final String[] RESERVED_SUFFIXES = {"_total", "_created", "_bucket", "_info"};
 
     /**
-     * Name is the name without suffix.
+     * Name without suffix.
+     * <p>
      * For example, the name for a counter "http_requests_total" is "http_requests".
-     * The name of an info called "target_info" is "target".
+     * The name of an info called "jvm_info" is "jvm".
+     * <p>
+     * We allow dots in label names. Dots are automatically replaced with underscores in Prometheus
+     * exposition formats. However, if metrics from this library are exposed in OpenTelemetry
+     * format dots are retained.
+     * <p>
      * See {@link #MetricMetadata(String, String, Unit)} for more info on naming conventions.
      */
     private final String name;
+
+    /**
+     * Same as name, except if name contains dots, then the prometheusName is {@code name.replace(".", "_")}.
+     */
+    private final String prometheusName;
+
+    /**
+     * optional, may be {@code null}.
+     */
     private final String help;
+
+    /**
+     * optional, may be {@code null}.
+     */
     private final Unit unit;
 
     /**
@@ -40,28 +49,10 @@ public MetricMetadata(String name, String help) {
     }
 
     /**
-     * Naming conventions:
-     * <ul>
-     *     <li>The name MUST NOT include the {@code _total} suffix for counter metrics or the
-     *         {@code _info} suffix for info metrics.
-     *         If in doubt, use {@link #sanitizeMetricName(String)} to remove the suffix.</li>
-     *     <li>If name is {@code null}, a {@link NullPointerException} is thrown.</li>
-     *     <li>If {@link #isValidMetricName(String) isValidMetricName(name)} is false,
-     *         an {@link IllegalArgumentException} is thrown.
-     *         Use {@link #sanitizeMetricName(String)} to convert arbitrary Strings to valid names.</li>
-     *     <li>If unit != null, the name SHOULD contain the unit as a suffix. Example:
-     *         <pre>
-     *         new MetricMetadata("cache_size_bytes", "current size of the cache", Unit.BYTES);
-     *         </pre>
-     *         This is not enforced. No Exception will be thrown if the name does not have the unit as suffix.</li>
-     *     <li>The name MUST NOT contain the {@code _total} or {@code _created} suffixes for counters,
-     *         the {@code _count}, {@code _sum}, or {@code _created} suffixes for summaries,
-     *         the {@code _count}, {@code _sum}, {@code _bucket}, or {@code _created} suffixes for classic histograms,
-     *         the {@code _gcount}, {@code _gsum}, {@code _bucket} suffixes for classic gauge histograms,
-     *         or the {@code _info} suffix for info metrics.</li>
-     * </ul>
-     *
-     * @param name must follow the naming conventions described above.
+     * Constructor.
+     * @param name must not be {@code null}. {@link PrometheusNaming#isValidMetricName(String) isValidMetricName(name)}
+     *             must be {@code true}. Use {@link PrometheusNaming#sanitizeMetricName(String)} to convert arbitrary
+     *             strings into valid names.
      * @param help optional. May be {@code null}.
      * @param unit optional. May be {@code null}.
      */
@@ -70,16 +61,29 @@ public MetricMetadata(String name, String help, Unit unit) {
         this.help = help;
         this.unit = unit;
         validate();
+        this.prometheusName = name.contains(".") ? PrometheusNaming.prometheusName(name) : name;
     }
 
     /**
      * The name does not include the {@code _total} suffix for counter metrics
      * or the {@code _info} suffix for Info metrics.
+     * <p>
+     * The name may contain dots. Use {@link #getPrometheusName()} to get the name in Prometheus format,
+     * i.e. with dots replaced by underscores.
      */
     public String getName() {
         return name;
     }
 
+    /**
+     * Same as {@link #getName()} but with dots replaced by underscores.
+     * <p>
+     * This is used by Prometheus exposition formats.
+     */
+    public String getPrometheusName() {
+        return prometheusName;
+    }
+
     public String getHelp() {
         return help;
     }
@@ -96,73 +100,10 @@ private void validate() {
         if (name == null) {
             throw new IllegalArgumentException("Missing required field: name is null");
         }
-        if (!isValidMetricName(name)) {
-            throw new IllegalArgumentException("'" + name + "': illegal metric name");
-        }
-    }
-
-    /**
-     * Test if a metric name is valid. Rules:
-     * <ul>
-     * <li>The name must match {@link #METRIC_NAME_RE}.</li>
-     * <li>The name MUST NOT end with one of the {@link #RESERVED_SUFFIXES}.</li>
-     * </ul>
-     * If a metric has a {@link Unit}, the metric name SHOULD end with the unit as a suffix (note that in
-     * <a href="https://openmetrics.io/">OpenMetrics</a> this is a MUST, but this library does not enforce Unit
-     * suffixes).
-     * <p>
-     * Example: If you create a Counter for a processing time with {@link Unit#SECONDS}, the name should be
-     * {@code processing_time_seconds}. When exposed in OpenMetrics Text format, this will be represented as two
-     * values: {@code processing_time_seconds_total} for the counter value, and the optional
-     * {@code processing_time_seconds_created} timestamp.
-     * <p>
-     * Use {@link #sanitizeMetricName(String)} to convert arbitrary Strings to valid metric names.
-     */
-    public static boolean isValidMetricName(String name) {
-        for (String reservedSuffix : RESERVED_SUFFIXES) {
-            if (name.endsWith(reservedSuffix)) {
-                return false;
-            }
-        }
-        return METRIC_NAME_RE.matcher(name).matches();
-    }
-
-    /**
-     * Convert arbitrary metric names to valid Prometheus metric names.
-     */
-    public static String sanitizeMetricName(String metricName) {
-        if (metricName.isEmpty()) {
-            throw new IllegalArgumentException("Cannot convert an empty string into a valid metric name.");
-        }
-        int length = metricName.length();
-        char[] sanitized = new char[length];
-        for (int i = 0; i < length; i++) {
-            char ch = metricName.charAt(i);
-            if (ch == ':' ||
-                    (ch >= 'a' && ch <= 'z') ||
-                    (ch >= 'A' && ch <= 'Z') ||
-                    (i > 0 && ch >= '0' && ch <= '9')) {
-                sanitized[i] = ch;
-            } else {
-                sanitized[i] = '_';
-            }
-        }
-        String sanitizedString = new String(sanitized);
-        boolean modified = true;
-        while (modified) {
-            modified = false;
-            for (String reservedSuffix : RESERVED_SUFFIXES) {
-                if (sanitizedString.equals(reservedSuffix)) {
-                    // This is for the corner case when you call sanitizeMetricName("_total").
-                    // In that case the result will be "total".
-                    return reservedSuffix.substring(1);
-                }
-                if (sanitizedString.endsWith(reservedSuffix)) {
-                    sanitizedString = sanitizedString.substring(0, sanitizedString.length() - reservedSuffix.length());
-                    modified = true;
-                }
-            }
+        String error = PrometheusNaming.validateMetricName(name);
+        if (error != null) {
+            throw new IllegalArgumentException("'" + name + "': Illegal metric name. " + error
+                    + " Call " + PrometheusNaming.class.getSimpleName() + ".sanitizeMetricName(name) to avoid this error.");
         }
-        return sanitizedString;
     }
 }
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshot.java
index 5108c3bd0..7faaa6399 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshot.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshot.java
@@ -20,10 +20,13 @@ protected MetricSnapshot(MetricMetadata metadata, DataPointSnapshot... data) {
     }
 
     protected MetricSnapshot(MetricMetadata metadata, Collection<? extends DataPointSnapshot> data) {
-        this.metadata = metadata;
+        if (metadata == null) {
+            throw new NullPointerException("metadata");
+        }
         if (data == null) {
-            throw new NullPointerException();
+            throw new NullPointerException("data");
         }
+        this.metadata = metadata;
         List<? extends DataPointSnapshot> dataCopy = new ArrayList<>(data);
         dataCopy.sort(Comparator.comparing(DataPointSnapshot::getLabels));
         this.data = Collections.unmodifiableList(dataCopy);
@@ -56,7 +59,7 @@ public static abstract class Builder<T extends Builder<T>> {
         /**
          * The name is required.
          * If the name is missing or invalid, {@code build()} will throw an {@link IllegalArgumentException}.
-         * See {@link MetricMetadata#isValidMetricName(String)} for info on valid metric names.
+         * See {@link PrometheusNaming#isValidMetricName(String)} for info on valid metric names.
          */
         public T withName(String name) {
             this.name = name;
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshots.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshots.java
index 98200461f..5308e6f98 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshots.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshots.java
@@ -7,6 +7,7 @@
 import java.util.List;
 import java.util.stream.Stream;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
 import static java.util.Collections.unmodifiableList;
 import static java.util.Comparator.comparing;
 
@@ -36,10 +37,10 @@ public MetricSnapshots(MetricSnapshot... snapshots) {
      */
     public MetricSnapshots(Collection<MetricSnapshot> snapshots) {
         List<MetricSnapshot> list = new ArrayList<>(snapshots);
-        list.sort(comparing(s -> s.getMetadata().getName()));
+        list.sort(comparing(s -> s.getMetadata().getPrometheusName()));
         for (int i = 0; i < snapshots.size() - 1; i++) {
-            if (list.get(i).getMetadata().getName().equals(list.get(i + 1).getMetadata().getName())) {
-                throw new IllegalArgumentException(list.get(i).getMetadata().getName() + ": duplicate metric name");
+            if (list.get(i).getMetadata().getPrometheusName().equals(list.get(i + 1).getMetadata().getPrometheusName())) {
+                throw new IllegalArgumentException(list.get(i).getMetadata().getPrometheusName() + ": duplicate metric name");
             }
         }
         this.snapshots = unmodifiableList(list);
@@ -79,7 +80,7 @@ private Builder() {
 
         public boolean containsMetricName(String name) {
             for (MetricSnapshot snapshot : snapshots) {
-                if (snapshot.getMetadata().getName().equals(name)) {
+                if (snapshot.getMetadata().getPrometheusName().equals(prometheusName(name))) {
                     return true;
                 }
             }
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/PrometheusNaming.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/PrometheusNaming.java
new file mode 100644
index 000000000..58de0c814
--- /dev/null
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/PrometheusNaming.java
@@ -0,0 +1,178 @@
+package io.prometheus.metrics.model.snapshots;
+
+import java.util.regex.Pattern;
+
+/**
+ * Utility for Prometheus Metric and Label naming.
+ * <p>
+ * Note that this library allows dots in metric and label names. Dots will automatically be replaced with underscores
+ * in Prometheus exposition formats. However, if metrics are exposed in OpenTelemetry format the dots are retained.
+ */
+public class PrometheusNaming {
+
+    /**
+     * Legal characters for metric names, including dot.
+     */
+    private static final Pattern METRIC_NAME_PATTERN = Pattern.compile("^[a-zA-Z_.:][a-zA-Z0-9_.:]+$");
+
+    /**
+     * Legal characters for label names, including dot.
+     */
+    private static final Pattern LABEL_NAME_PATTERN = Pattern.compile("^[a-zA-Z_.][a-zA-Z0-9_.]*$");
+
+    /**
+     * According to OpenMetrics {@code _count} and {@code _sum} (and {@code _gcount}, {@code _gsum}) should also be
+     * reserved metric name suffixes. However, popular instrumentation libraries have Gauges with names
+     * ending in {@code _count}.
+     * Examples:
+     * <ul>
+     * <li>Micrometer: {@code jvm_buffer_count}</li>
+     * <li>OpenTelemetry: {@code process_runtime_jvm_buffer_count}</li>
+     * </ul>
+     * We do not treat {@code _count} and {@code _sum} as reserved suffixes here for compatibility with these libraries.
+     * However, there is a risk of name conflict if someone creates a gauge named {@code my_data_count} and a
+     * histogram or summary named {@code my_data}, because the histogram or summary will implicitly have a sample
+     * named {@code my_data_count}.
+     */
+    private static final String[] RESERVED_METRIC_NAME_SUFFIXES = {
+            "_total", "_created", "_bucket", "_info",
+            ".total", ".created", ".bucket", ".info"
+    };
+
+    /**
+     * Test if a metric name is valid. Rules:
+     * <ul>
+     * <li>The name must match {@link #METRIC_NAME_PATTERN}.</li>
+     * <li>The name MUST NOT end with one of the {@link #RESERVED_METRIC_NAME_SUFFIXES}.</li>
+     * </ul>
+     * If a metric has a {@link Unit}, the metric name SHOULD end with the unit as a suffix.
+     * Note that <a href="https://openmetrics.io/">OpenMetrics</a> requires metric names to have their unit as suffix,
+     * and we implement this in {@code prometheus-metrics-core}. However, {@code prometheus-metrics-model}
+     * does not enforce Unit suffixes.
+     * <p>
+     * Example: If you create a Counter for a processing time with Unit {@link Unit#SECONDS SECONDS},
+     * the name should be {@code processing_time_seconds}. When exposed in OpenMetrics Text format,
+     * this will be represented as two values: {@code processing_time_seconds_total} for the counter value,
+     * and the optional {@code processing_time_seconds_created} timestamp.
+     * <p>
+     * Use {@link #sanitizeMetricName(String)} to convert arbitrary Strings to valid metric names.
+     */
+    public static boolean isValidMetricName(String name) {
+        return validateMetricName(name) == null;
+    }
+
+    /**
+     * Same as {@link #isValidMetricName(String)}, but produces an error message.
+     * <p>
+     * The name is valid if the error message is {@code null}.
+     */
+    static String validateMetricName(String name) {
+        for (String reservedSuffix : RESERVED_METRIC_NAME_SUFFIXES) {
+            if (name.endsWith(reservedSuffix)) {
+                return "The metric name must not include the '" + reservedSuffix + "' suffix.";
+            }
+        }
+        if (!METRIC_NAME_PATTERN.matcher(name).matches()) {
+            return "The metric name contains unsupported characters";
+        }
+        return null;
+    }
+
+    public static boolean isValidLabelName(String name) {
+        return LABEL_NAME_PATTERN.matcher(name).matches() &&
+                !(name.startsWith("__") || name.startsWith("._") || name.startsWith("..") || name.startsWith("_."));
+    }
+
+    /**
+     * Get the metric or label name that is used in Prometheus exposition format.
+     *
+     * @param name must be a valid metric or label name,
+     *             i.e. {@link #isValidMetricName(String) isValidMetricName(name)}
+     *             or {@link #isValidLabelName(String) isValidLabelName(name)}  must be true.
+     * @return the name with dots replaced by underscores.
+     */
+    public static String prometheusName(String name) {
+        return name.replace(".", "_");
+    }
+
+    /**
+     * Convert an arbitrary string to a name where {@link #isValidMetricName(String) isValidMetricName(name)} is true.
+     */
+    public static String sanitizeMetricName(String metricName) {
+        if (metricName.isEmpty()) {
+            throw new IllegalArgumentException("Cannot convert an empty string to a valid metric name.");
+        }
+        String sanitizedName = replaceIllegalCharsInMetricName(metricName);
+        boolean modified = true;
+        while (modified) {
+            modified = false;
+            for (String reservedSuffix : RESERVED_METRIC_NAME_SUFFIXES) {
+                if (sanitizedName.equals(reservedSuffix)) {
+                    // This is for the corner case when you call sanitizeMetricName("_total").
+                    // In that case the result will be "total".
+                    return reservedSuffix.substring(1);
+                }
+                if (sanitizedName.endsWith(reservedSuffix)) {
+                    sanitizedName = sanitizedName.substring(0, sanitizedName.length() - reservedSuffix.length());
+                    modified = true;
+                }
+            }
+        }
+        return sanitizedName;
+    }
+
+    /**
+     * Convert an arbitrary string to a name where {@link #isValidLabelName(String) isValidLabelName(name)} is true.
+     */
+    public static String sanitizeLabelName(String labelName) {
+        if (labelName.isEmpty()) {
+            throw new IllegalArgumentException("Cannot convert an empty string to a valid label name.");
+        }
+        String sanitizedName = replaceIllegalCharsInLabelName(labelName);
+        while (sanitizedName.startsWith("__") || sanitizedName.startsWith("_.") || sanitizedName.startsWith("._") || sanitizedName.startsWith("..")) {
+            sanitizedName = sanitizedName.substring(1);
+        }
+        return sanitizedName;
+    }
+
+    /**
+     * Returns a string that matches {@link #METRIC_NAME_PATTERN}.
+     */
+    private static String replaceIllegalCharsInMetricName(String name) {
+        int length = name.length();
+        char[] sanitized = new char[length];
+        for (int i = 0; i < length; i++) {
+            char ch = name.charAt(i);
+            if (ch == ':' ||
+                    ch == '.' ||
+                    (ch >= 'a' && ch <= 'z') ||
+                    (ch >= 'A' && ch <= 'Z') ||
+                    (i > 0 && ch >= '0' && ch <= '9')) {
+                sanitized[i] = ch;
+            } else {
+                sanitized[i] = '_';
+            }
+        }
+        return new String(sanitized);
+    }
+
+    /**
+     * Returns a string that matches {@link #LABEL_NAME_PATTERN}.
+     */
+    private static String replaceIllegalCharsInLabelName(String name) {
+        int length = name.length();
+        char[] sanitized = new char[length];
+        for (int i = 0; i < length; i++) {
+            char ch = name.charAt(i);
+            if (ch == '.' ||
+                    (ch >= 'a' && ch <= 'z') ||
+                    (ch >= 'A' && ch <= 'Z') ||
+                    (i > 0 && ch >= '0' && ch <= '9')) {
+                sanitized[i] = ch;
+            } else {
+                sanitized[i] = '_';
+            }
+        }
+        return new String(sanitized);
+    }
+}
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/StateSetSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/StateSetSnapshot.java
index 4cad4ac11..9b0c4f07d 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/StateSetSnapshot.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/StateSetSnapshot.java
@@ -30,8 +30,8 @@ private void validate() {
             throw new IllegalArgumentException("An state set metric cannot have a unit.");
         }
         for (StateSetDataPointSnapshot entry : getData()) {
-            if (entry.getLabels().contains(getMetadata().getName())) {
-                throw new IllegalArgumentException("Label name " + getMetadata().getName() + " is reserved.");
+            if (entry.getLabels().contains(getMetadata().getPrometheusName())) {
+                throw new IllegalArgumentException("Label name " + getMetadata().getPrometheusName() + " is reserved.");
             }
         }
     }
diff --git a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/registry/PrometheusRegistryTest.java b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/registry/PrometheusRegistryTest.java
new file mode 100644
index 000000000..8519f5f27
--- /dev/null
+++ b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/registry/PrometheusRegistryTest.java
@@ -0,0 +1,82 @@
+package io.prometheus.metrics.model.registry;
+
+import io.prometheus.metrics.model.snapshots.CounterSnapshot;
+import io.prometheus.metrics.model.snapshots.GaugeSnapshot;
+import io.prometheus.metrics.model.snapshots.MetricSnapshot;
+import io.prometheus.metrics.model.snapshots.MetricSnapshots;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class PrometheusRegistryTest {
+
+    Collector noName = new Collector() {
+        @Override
+        public MetricSnapshot collect() {
+            return GaugeSnapshot.newBuilder()
+                    .withName("no_name_gauge")
+                    .build();
+        }
+
+        @Override
+        public String getPrometheusName() {
+            return null;
+        }
+    };
+
+    Collector counterA1 = () -> CounterSnapshot.newBuilder()
+            .withName("counter_a")
+            .build();
+
+    Collector counterA2 = () -> CounterSnapshot.newBuilder()
+            .withName("counter.a")
+            .build();
+
+    Collector counterB = () -> CounterSnapshot.newBuilder()
+            .withName("counter_b")
+            .build();
+
+    Collector gaugeA = () -> GaugeSnapshot.newBuilder()
+            .withName("gauge_a")
+            .build();
+
+    @Test
+    public void registerNoName() {
+        PrometheusRegistry registry = new PrometheusRegistry();
+        // If the collector does not have a name at registration time, there is no conflict during registration.
+        registry.register(noName);
+        registry.register(noName);
+        // However, at scrape time the collector has to provide a metric name, and then we'll get a duplicat name error.
+        try {
+            registry.scrape();
+        } catch (IllegalStateException e) {
+            Assert.assertTrue(e.getMessage().contains("duplicate") && e.getMessage().contains("no_name_gauge"));
+            return;
+        }
+        Assert.fail("Expected duplicate name exception");
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void registerDuplicateName() {
+        PrometheusRegistry registry = new PrometheusRegistry();
+        registry.register(counterA1);
+        registry.register(counterA2);
+    }
+
+    @Test
+    public void registerOk() {
+        PrometheusRegistry registry = new PrometheusRegistry();
+        registry.register(counterA1);
+        registry.register(counterB);
+        registry.register(gaugeA);
+        MetricSnapshots snapshots = registry.scrape();
+        Assert.assertEquals(3, snapshots.size());
+
+        registry.unregister(counterB);
+        snapshots = registry.scrape();
+        Assert.assertEquals(2, snapshots.size());
+
+        registry.register(counterB);
+        snapshots = registry.scrape();
+        Assert.assertEquals(3, snapshots.size());
+    }
+}
diff --git a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/GaugeSnapshotTest.java b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/GaugeSnapshotTest.java
index 20a094a23..d4e2fec33 100644
--- a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/GaugeSnapshotTest.java
+++ b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/GaugeSnapshotTest.java
@@ -87,6 +87,11 @@ public void testTotalSuffixPresent() {
         CounterSnapshot.newBuilder().withName("test_total").build();
     }
 
+    @Test(expected = IllegalArgumentException.class)
+    public void testTotalSuffixPresentDot() {
+        CounterSnapshot.newBuilder().withName("test.total").build();
+    }
+
     @Test(expected = IllegalArgumentException.class)
     public void testValueMissing() {
         CounterDataPointSnapshot.newBuilder().build();
diff --git a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/InfoSnapshotTest.java b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/InfoSnapshotTest.java
index e5b7d55be..c2fd2af63 100644
--- a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/InfoSnapshotTest.java
+++ b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/InfoSnapshotTest.java
@@ -43,4 +43,18 @@ public void testDataImmutable() {
         iterator.next();
         iterator.remove();
     }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testNameMustNotIncludeSuffix() {
+        InfoSnapshot.newBuilder()
+                .withName("jvm_info")
+                .build();
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testNameMustNotIncludeSuffixDot() {
+        InfoSnapshot.newBuilder()
+                .withName("jvm.info")
+                .build();
+    }
 }
diff --git a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/LabelsTest.java b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/LabelsTest.java
index 8eaa8333a..d7a3e8b3e 100644
--- a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/LabelsTest.java
+++ b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/LabelsTest.java
@@ -2,8 +2,10 @@
 
 import io.prometheus.metrics.model.snapshots.Labels;
 import org.junit.Assert;
+import org.junit.Ignore;
 import org.junit.Test;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.sanitizeLabelName;
 import static org.junit.Assert.assertNotEquals;
 
 public class LabelsTest {
@@ -47,6 +49,20 @@ public void testCompareDifferentNumberOfLabels() {
         assertNotEquals(labels2, labels1);
     }
 
+    @Test
+    public void testComparePrometheusNames() {
+        Labels labels1 = Labels.of("my_a", "val");
+        Labels labels2 = Labels.of("my.b", "val");
+        assertLessThan(labels1, labels2); // this is true because it compares "my_a" to "my_b".
+    }
+
+    @Test
+    public void testEqualsHashcodeDots() {
+        Labels labels1 = Labels.of("my_a", "val");
+        Labels labels2 = Labels.of("my.a", "val");
+        Assert.assertEquals(labels1, labels2);
+        Assert.assertEquals(labels1.hashCode(), labels2.hashCode());
+    }
 
     @Test
     public void testCompareEquals() {
@@ -60,7 +76,7 @@ public void testCompareEquals() {
 
     @Test(expected = IllegalArgumentException.class)
     public void testIllegalLabelName() {
-        Labels.of("http.status_code", "200");
+        Labels.of("my_service/status", "200");
     }
 
     @Test(expected = IllegalArgumentException.class)
@@ -68,13 +84,48 @@ public void testReservedLabelName() {
         Labels.of("__name__", "requests_total");
     }
 
+    @Test(expected = IllegalArgumentException.class)
+    public void testDuplicateLabelName() {
+        Labels.of("name1", "value1", "name2", "value2", "name1", "value3");
+    }
+
     @Test
-    public void testSanitizeLabelName() {
-        Assert.assertEquals("_my_label", Labels.sanitizeLabelName("...my/label"));
+    public void testMakePrometheusNames() {
+        String[] names = new String[]{};
+        String[] prometheusNames = Labels.makePrometheusNames(names);
+        Assert.assertSame(names, prometheusNames);
+
+        names = new String[]{"no_dots", "at_all"};
+        prometheusNames = Labels.makePrometheusNames(names);
+        Assert.assertSame(names, prometheusNames);
+
+        names = new String[]{"dots", "here.it.is"};
+        prometheusNames = Labels.makePrometheusNames(names);
+        Assert.assertNotSame(names, prometheusNames);
+        Assert.assertSame(names[0], prometheusNames[0]);
+        Assert.assertEquals("here.it.is", names[1]);
+        Assert.assertEquals("here_it_is", prometheusNames[1]);
+    }
+
+    @Test
+    public void testMerge() {
+        Labels labels1 = Labels.of("key.1", "value 1", "key.3", "value 3");
+        Labels labels2 = Labels.of("key_2", "value 2");
+        Labels merged = labels2.merge(labels1);
+        Assert.assertEquals("key.1", merged.getName(0));
+        Assert.assertEquals("key_2", merged.getName(1));
+        Assert.assertEquals("key.3", merged.getName(2));
     }
 
     @Test(expected = IllegalArgumentException.class)
-    public void testDuplicateLabelName() {
-        Labels.of("name1", "value1", "name2", "value2", "name1", "value3");
+    public void testMergeDuplicateName() {
+        Labels labels1 = Labels.of("key_one", "v1");
+        Labels labels2 = Labels.of("key.one", "v2");
+        labels2.merge(labels1);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testDuplicateName() {
+        Labels.of("key_one", "v1", "key.one", "v2");
     }
 }
diff --git a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricMetadataTest.java b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricMetadataTest.java
index a655954f7..6e76f724a 100644
--- a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricMetadataTest.java
+++ b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/MetricMetadataTest.java
@@ -1,10 +1,11 @@
 package io.prometheus.metrics.model.snapshots;
 
-import io.prometheus.metrics.model.snapshots.MetricMetadata;
-import io.prometheus.metrics.model.snapshots.Unit;
 import org.junit.Assert;
 import org.junit.Test;
 
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.sanitizeMetricName;
+
 public class MetricMetadataTest {
 
     @Test(expected = IllegalArgumentException.class)
@@ -19,37 +20,38 @@ public void testNullName() {
 
     @Test(expected = IllegalArgumentException.class)
     public void testIllegalName() {
-        new MetricMetadata("http.server.duration");
+        new MetricMetadata("my_namespace/http_server_duration"); // let's see when we decide to allow slashes :)
     }
 
     @Test
     public void testSanitizationIllegalCharacters() {
-        MetricMetadata metadata = new MetricMetadata(MetricMetadata.sanitizeMetricName("http.server.duration"), "help string", Unit.SECONDS);
-        Assert.assertEquals("http_server_duration", metadata.getName());
+        MetricMetadata metadata = new MetricMetadata(sanitizeMetricName("my_namespace/http.server.duration"), "help string", Unit.SECONDS);
+        Assert.assertEquals("my_namespace_http.server.duration", metadata.getName());
+        Assert.assertEquals("my_namespace_http_server_duration", metadata.getPrometheusName());
         Assert.assertEquals("help string", metadata.getHelp());
         Assert.assertEquals("seconds", metadata.getUnit().toString());
     }
 
     @Test
     public void testSanitizationCounter() {
-        MetricMetadata metadata = new MetricMetadata(MetricMetadata.sanitizeMetricName("my_events_total"));
+        MetricMetadata metadata = new MetricMetadata(sanitizeMetricName("my_events_total"));
         Assert.assertEquals("my_events", metadata.getName());
     }
 
     @Test
     public void testSanitizationInfo() {
-        MetricMetadata metadata = new MetricMetadata(MetricMetadata.sanitizeMetricName("target_info"));
+        MetricMetadata metadata = new MetricMetadata(sanitizeMetricName("target_info"));
         Assert.assertEquals("target", metadata.getName());
     }
 
     @Test
     public void testSanitizationWeirdCornerCase() {
-        MetricMetadata metadata = new MetricMetadata(MetricMetadata.sanitizeMetricName("_total_created"));
+        MetricMetadata metadata = new MetricMetadata(sanitizeMetricName("_total_created"));
         Assert.assertEquals("total", metadata.getName());
     }
 
     @Test(expected = IllegalArgumentException.class)
     public void testSanitizeEmptyString() {
-        MetricMetadata.sanitizeMetricName("");
+        sanitizeMetricName("");
     }
 }
diff --git a/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/PrometheusNamingTest.java b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/PrometheusNamingTest.java
new file mode 100644
index 000000000..d9ba9339d
--- /dev/null
+++ b/prometheus-metrics-model/src/test/java/io/prometheus/metrics/model/snapshots/PrometheusNamingTest.java
@@ -0,0 +1,34 @@
+package io.prometheus.metrics.model.snapshots;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.prometheusName;
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.sanitizeLabelName;
+import static io.prometheus.metrics.model.snapshots.PrometheusNaming.sanitizeMetricName;
+
+public class PrometheusNamingTest {
+
+    @Test
+    public void testSanitizeMetricName() {
+        Assert.assertEquals("_abc_def", prometheusName(sanitizeMetricName("0abc.def")));
+        Assert.assertEquals("___ab_:c0", prometheusName(sanitizeMetricName("___ab.:c0")));
+        Assert.assertEquals("my_prefix_my_metric", sanitizeMetricName("my_prefix/my_metric"));
+        Assert.assertEquals("my_counter", prometheusName(sanitizeMetricName("my_counter_total")));
+        Assert.assertEquals("jvm", sanitizeMetricName("jvm.info"));
+        Assert.assertEquals("jvm", sanitizeMetricName("jvm_info"));
+        Assert.assertEquals("jvm", sanitizeMetricName("jvm.info"));
+        Assert.assertEquals("a.b", sanitizeMetricName("a.b"));
+    }
+
+    @Test
+    public void testSanitizeLabelName() {
+        Assert.assertEquals("_abc_def", prometheusName(sanitizeLabelName("0abc.def")));
+        Assert.assertEquals("_abc", prometheusName(sanitizeLabelName("_abc")));
+        Assert.assertEquals("_abc", prometheusName(sanitizeLabelName("__abc")));
+        Assert.assertEquals("_abc", prometheusName(sanitizeLabelName("___abc")));
+        Assert.assertEquals("_abc", prometheusName(sanitizeLabelName("_.abc")));
+        Assert.assertEquals("abc.def", sanitizeLabelName("abc.def"));
+        Assert.assertEquals("abc.def2", sanitizeLabelName("abc.def2"));
+    }
+}