Issue WICG#196 - Add a Sec-CH-UA-Version-List client hint

index.bs

@@ -652,10 +652,37 @@ The header's ABNF is:
   Sec-CH-UA-Platform-Version = sf-string
 ```
 
+The 'Sec-CH-UA-Version-List' Header Field {#sec-ch-ua-version-list}
+--------------------------------
+
+The <dfn http-header>`Sec-CH-UA-Version-List`</dfn> request header field gives a server information
+about the [=user agent/full version=] for each brand in its [=brands=] list. It is a
+[=Structured Header=] whose value MUST be a [=structured header/list=] [[!RFC8941]].
+
+The header's ABNF is:
+
+``` abnf
+  Sec-CH-UA-Version-List = sf-list
+```
+
+To <dfn abstract-op>return the `Sec-CH-UA-Version-List` value for a request</dfn>, [=user agents=]
+MUST run the following steps:
+
+1. Let |versionList| be a [=/list=], initially empty.
+1. Let |brands| be the result of running the [=create brands=] steps, with
+    [=user agent/full version=] passed as an argument.
+1. For each |brand| in |brands|:
+    1. Let |parameter| be a [=dictionary=], initially empty.
+    1. Set |parameter|["param_name"] to "v".
+    1. Set |parameter|["param_value"] to |brand|'s {{NavigatorUABrandVersion/version}}.
+    1. Let |pair| be a tuple comprised of |brand|'s {{NavigatorUABrandVersion/brand}} and
+        |parameter|.
+    1. Append |pair| to |versionList|.
+1. Return the output of running [=serializing a list=] with |versionList| as input.
+
 Note: These client hints can be evoked with the following set of [=client hints tokens=]:
 `Sec-CH-UA`, `Sec-CH-UA-Arch`, `Sec-CH-UA-Bitness`, `Sec-CH-UA-Full-Version`, `Sec-CH-UA-Mobile`,
-`Sec-CH-UA-Model`, `Sec-CH-UA-Platform`, `Sec-CH-UA-Platform-Version`
-
+`Sec-CH-UA-Model`, `Sec-CH-UA-Platform`, `Sec-CH-UA-Platform-Version`, `Sec-CH-UA-Version-List`
 
 Interface {#interface}
 =================
@@ -669,12 +696,13 @@ dictionary NavigatorUABrandVersion {
 dictionary UADataValues {
   sequence&lt;NavigatorUABrandVersion&gt; brands;
   boolean mobile;
-  DOMString platform;
   DOMString architecture;
   DOMString bitness;
   DOMString model;
+  DOMString platform;
   DOMString platformVersion;
   DOMString uaFullVersion;
+  sequence&lt;NavigatorUABrandVersion&gt; versionList;
 };
 
 dictionary UALowEntropyJSON {
@@ -797,7 +825,6 @@ ISSUE(wicg/ua-client-hints): We can improve upon when and why a UA decides to re
 3. Otherwise, run the following steps [=in parallel=]:
 
     1. Let |uaData| be a new {{UADataValues}}.
-
     1. set |uaData|["{{UADataValues/brands}}"] to [=this=]'s [=relevant global object=]'s [=WindowOrWorkerGlobalScope/brands frozen array=].
     1. set |uaData|["{{UADataValues/mobile}}"] to the [=user agent=]'s [=user agent/mobileness=].
     1. set |uaData|["{{UADataValues/platform}}"] to the [=user agent=]'s [=user agent/platform brand=].
@@ -811,6 +838,9 @@ ISSUE(wicg/ua-client-hints): We can improve upon when and why a UA decides to re
         to the [=user agent=]'s [=user agent/platform version=].
     1. If |hints| [=list/contains=] "uaFullVersion", let |uaData|["{{UADataValues/uaFullVersion}}"]
         be the the user agent's [=user agent/full version=].
+    1. If |hints| [=list/contains=] "versionList", let |uaData|["{{UADataValues/versionList}}"]
+        be the result of running the [=create brands=] steps, with [=user agent/full version=]
+        passed as an argument.
     1. [=Queue a task=] on the [=permission task source=] to [=resolve=] |p| with |uaData|.
 
 4.  Return |p|.
@@ -950,9 +980,9 @@ IANA Considerations {#iana}
 ===================
 
 This document intends to define the `Sec-CH-UA`, `Sec-CH-UA-Arch`, `Sec-CH-UA-Bitness`,
-`Sec-CH-UA-Full-Version`, `Sec-CH-UA-Mobile`, `Sec-CH-UA-Model`, `Sec-CH-UA-Platform`, and the
-`Sec-CH-UA-Platform-Version` HTTP request header fields, and register them in the permanent message
-header field registry ([[RFC3864]]).
+`Sec-CH-UA-Full-Version`, `Sec-CH-UA-Mobile`, `Sec-CH-UA-Model`, `Sec-CH-UA-Platform`,
+`Sec-CH-UA-Platform-Version`, and the `Sec-CH-UA-Version-List` HTTP request header fields, and
+register them in the permanent message header field registry ([[RFC3864]]).
 
 It also intends to deprecate usage of the `User-Agent` header field.
 
@@ -1060,6 +1090,19 @@ Author/Change controller: IETF
 
 Specification document: this specification ([[#sec-ch-ua-platform-version]])
 
+'Sec-CH-UA-Version-List' Header Field {#iana-version-list}
+-------------------------
+
+Header field name: Sec-CH-UA-Version-List
+
+Applicable protocol: http
+
+Status: standard
+
+Author/Change controller: IETF
+
+Specification document: this specification ([[#sec-ch-ua-version-list]])
+
 'User-Agent' Header Field {#iana-user-agent}
 -------------------------