edit descriptions

reference/settings.v3.yml

@@ -1431,14 +1431,14 @@ paths:
       description: Update inventory settings
   /settings/store/units-of-measurement:
     get:
-      summary: Get Store Units of Measurement Notifications Settings
+      summary: Get Units of Measurement Settings
       description: |- 
-        Get a store's notification settings for its units of measurements.
+        Get settings for [units of measurements](https://support.bigcommerce.com/s/article/Store-Settings?language=en_US#physical).
       tags:
         - Units of Measurement
       responses:
         '200':
-          description: 'OK, null indicates that a particular field has not been overridden on a channel level when channel level settings are requested'
+          description: 'OK. When you request channel-level settings, `null` indicates that a channel does not have overrides.'
           content:
             application/json:
               schema:
@@ -1449,26 +1449,33 @@ paths:
                   meta:
                     type: object
         '422':
-          description: Provided settings could not be applied for some reason - detailed errors in the response.
+          description: The provided settings could not be applied. See detailed errors in the response.
           content:
             application/json:
               schema:
                 $ref: '#/components/schemas/ErrorResponse'
       parameters:
         - $ref: '#/components/parameters/ChannelIdParam'
     put:
-      summary: Update Store Units of Measurements Notifications Settings
+      summary: Update Units of Measurement Settings
       description: |- 
-        Update a store's notification settings for its units of measurements.
+        Update settings for [units of measurements](https://support.bigcommerce.com/s/article/Store-Settings?language=en_US#physical).
+
+        The endpoint does not support partial updates. Provide all fields to update global or channel-level settings.
+
+        Create channel-level settings, or overrides for a channel, using the `channel_id`  query parameter. 
+
+        To delete overrides for a channel, supply `null` as a value for all fields. A channel then inherits global values.
+
+        The endpoint does not support 'null' as a value for global-level settings.
       requestBody:
         content:
           application/json:
             schema:
               $ref: '#/components/schemas/MeasurementUnitsSettings'
-        description: null set for a particular field removes override on a channel level and means inheritance from a global level
       responses:
         '200':
-          description: 'OK, null indicates that a particular field has not been overridden on a channel level when channel level settings are requested'
+          description: 'OK. When you request channel-level settings, `null` indicates that a channel does not have overrides.'
           content:
             application/json:
               schema: