feat(http): Add Sec-CH-UA-Form-Factors, Sec-CH-UA-WoW64 headers

files/en-us/web/http/client_hints/index.md

@@ -63,10 +63,16 @@ For example, to stop requesting any hints it would send `Accept-CH` with an empt
 ## Low entropy hints
 
 Client hints are broadly divided into high and low entropy hints.
-
 The low entropy hints are those that don't give away much information that might be used to create a [fingerprinting](/en-US/docs/Glossary/Fingerprinting) for a user.
 They may be sent by default on every client request, irrespective of the server `Accept-CH` response header, depending on the permission policy.
-These hints include: {{HTTPHeader("Save-Data")}}, {{HTTPHeader("Sec-CH-UA")}}, {{HTTPHeader("Sec-CH-UA-Mobile")}}, {{HTTPHeader("Sec-CH-UA-Platform")}}.
+Low entropy hints are:
+
+- {{HTTPHeader("Save-Data")}},
+- {{HTTPHeader("Sec-CH-UA")}},
+- {{HTTPHeader("Sec-CH-UA-Mobile")}}, and
+- {{HTTPHeader("Sec-CH-UA-Platform")}}.
+
+## High entropy hints
 
 The high entropy hints are those that have the potential to give away more information that can be used for user fingerprinting, and therefore are gated in such a way that the user agent can make a decision whether to provide them.
 The decision might be based on user preferences, a permission request, or the permission policy.

files/en-us/web/http/headers/sec-ch-ua-arch/index.md

@@ -55,7 +55,7 @@ The client may choose to provide the hint, and add the `Sec-CH-UA-Arch` header t
 For example, on a Windows X86 based computer, the client might add the header as shown:
 
 ```http
-GET /GET /my/page HTTP/1.1
+GET /my/page HTTP/1.1
 Host: example.site
 
 Sec-CH-UA: " Not A;Brand";v="99", "Chromium";v="96", "Google Chrome";v="96"

files/en-us/web/http/headers/sec-ch-ua-bitness/index.md

@@ -56,7 +56,7 @@ The client may choose to provide the hint, and add the `Sec-CH-UA-Bitness` heade
 For example, on a Windows based 64-bit computer, the client might add the header as shown:
 
 ```http
-GET /GET /my/page HTTP/1.1
+GET /my/page HTTP/1.1
 Host: example.site
 
 Sec-CH-UA: " Not A;Brand";v="99", "Chromium";v="96", "Google Chrome";v="96"

files/en-us/web/http/headers/sec-ch-ua-form-factors/index.md

@@ -0,0 +1,96 @@
+---
+title: Sec-CH-UA-Form-Factors
+slug: Web/HTTP/Headers/Sec-CH-UA-Form-Factors
+page-type: http-header
+status:
+  - experimental
+spec-urls: https://wicg.github.io/ua-client-hints/#sec-ch-ua-form-factors
+---
+
+{{HTTPSidebar}}{{SecureContext_Header}}
+
+The HTTP **`Sec-CH-UA-Form-Factors`** {{Glossary("request header")}} is a [user agent client hint](/en-US/docs/Web/HTTP/Client_hints#user-agent_client_hints) which provides information on the user-agent's device form factor.
+
+<table class="properties">
+  <tbody>
+    <tr>
+      <th scope="row">Header type</th>
+      <td>
+        {{Glossary("Request header")}},
+        <a href="/en-US/docs/Web/HTTP/Client_hints">Client hint</a>
+      </td>
+    </tr>
+    <tr>
+      <th scope="row">{{Glossary("Forbidden header name")}}</th>
+      <td>Yes (<code>Sec-</code> prefix)</td>
+    </tr>
+  </tbody>
+</table>
+
+## Syntax
+
+```http
+Sec-CH-UA-Form-Factors: <form-factor>
+Sec-CH-UA-Form-Factors: <form-factor>, …, <form-factor>
+```
+
+### Directives
+
+- `<form-factor>`
+  - : A string indicating a common device form factor.
+    All applicable form factors can be included.
+    The meanings of the allowed values are:
+    - `"Desktop"`
+      - : A user-agent running on a personal computer.
+    - `"Automotive"`
+      - : A user-agent embedded in a vehicle, where the user may be responsible for operating the vehicle and unable to attend to small details.
+    - `"Mobile"`
+      - : Small, touch-oriented device typically carried on a user's person.
+    - `"Tablet"`
+      - : A touch-oriented device larger than `"Mobile"` and not typically carried on a user's person.
+    - `"XR"`
+      - : Immersive devices that augment or replace the environment around the user.
+    - `"EInk"`
+      - : A device characterized by slow screen updates and limited or no color resolution.
+    - `"Watch"`
+      - : A mobile device with a tiny screen (typically less than 2 inches), carried in such a way that the user can glance at it quickly.
+
+## Examples
+
+### Using Sec-CH-UA-Form-Factors
+
+A server requests the `Sec-CH-UA-Form-Factors` header by including the {{HTTPHeader("Accept-CH")}} in a _response_ to any request from the client, using the name of the desired header as a token:
+
+```http
+HTTP/1.1 200 OK
+Accept-CH: Sec-CH-UA-Form-Factors
+```
+
+The client may choose to provide the hint, and add the `Sec-CH-UA-Form-Factors` header to subsequent requests.
+For example, the client might add the header as shown:
+
+```http
+GET /my/page HTTP/1.1
+Host: example.site
+
+Sec-CH-UA-Mobile: ?0
+Sec-CH-UA-Form-Factors: "EInk"
+```
+
+In this case, `"EInk"` means that the device is characterized by slow screen updates and limited color resolution, and as such, responses may differ depending on this hint.
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- [Client hints](/en-US/docs/Web/HTTP/Client_hints)
+- [User-Agent Client Hints API](/en-US/docs/Web/API/User-Agent_Client_Hints_API)
+- {{HTTPHeader("Accept-CH")}}
+- [HTTP Caching: Vary](/en-US/docs/Web/HTTP/Caching#vary) and {{HTTPHeader("Vary")}} header
+- [Improving user privacy and developer experience with User-Agent Client Hints](https://developer.chrome.com/docs/privacy-security/user-agent-client-hints) on developer.chrome.com

files/en-us/web/http/headers/sec-ch-ua-full-version/index.md

@@ -56,7 +56,7 @@ The client may choose to provide the hint, and add the `Sec-CH-UA-Full-Version`
 For example, the client might add the header as shown:
 
 ```http
-GET /GET /my/page HTTP/1.1
+GET /my/page HTTP/1.1
 Host: example.site
 
 Sec-CH-UA: " Not A;Brand";v="99", "Chromium";v="96", "Google Chrome";v="96"

files/en-us/web/http/headers/sec-ch-ua-model/index.md

@@ -53,7 +53,7 @@ The client may choose to provide the hint, and add the `Sec-CH-UA-Model` header
 For example, on mobile phone the client might add the header as shown:
 
 ```http
-GET /GET /my/page HTTP/1.1
+GET /my/page HTTP/1.1
 Host: example.site
 
 Sec-CH-UA: " Not A;Brand";v="99", "Chromium";v="96", "Google Chrome";v="96"

files/en-us/web/http/headers/sec-ch-ua-platform-version/index.md

@@ -54,7 +54,7 @@ The client may choose to provide the hint, and add the `Sec-CH-UA-Platform-Versi
 For example, the following request headers might be sent from a browser running on Windows 10.
 
 ```http
-GET /GET /my/page HTTP/1.1
+GET /my/page HTTP/1.1
 Host: example.site
 
 Sec-CH-UA: " Not A;Brand";v="99", "Chromium";v="96", "Google Chrome";v="96"

files/en-us/web/http/headers/sec-ch-ua-wow64/index.md

@@ -0,0 +1,81 @@
+---
+title: Sec-CH-UA-WoW64
+slug: Web/HTTP/Headers/Sec-CH-UA-WoW64
+page-type: http-header
+status:
+  - experimental
+spec-urls: https://wicg.github.io/ua-client-hints/#sec-ch-ua-wow64
+---
+
+{{HTTPSidebar}}{{SecureContext_Header}}
+
+The HTTP **`Sec-CH-UA-WoW64`** {{Glossary("request header")}} is a [user agent client hint](/en-US/docs/Web/HTTP/Client_hints#user-agent_client_hints) indicating if a 32-bit User-Agent application is running on a 64-bit Windows machine.
+
+[WoW64](https://en.wikipedia.org/wiki/WoW64) was commonly used to know which NPAPI plugin installer should be offered for download.
+This client hint header is used for backwards compatibility considerations, to provide a one-to-one mapping from the User-Agent string of certain browsers to UA client hints.
+
+<table class="properties">
+  <tbody>
+    <tr>
+      <th scope="row">Header type</th>
+      <td>
+        {{Glossary("Request header")}},
+        <a href="/en-US/docs/Web/HTTP/Client_hints">Client hint</a>
+      </td>
+    </tr>
+    <tr>
+      <th scope="row">{{Glossary("Forbidden header name")}}</th>
+      <td>Yes (<code>Sec-</code> prefix)</td>
+    </tr>
+  </tbody>
+</table>
+
+## Syntax
+
+```http
+Sec-CH-UA-WoW64: <boolean>
+```
+
+### Directives
+
+- `<boolean>`
+  - : `?1` means the user agent's binary is running in 32-bit mode on 64-bit Windows (true) and `?0` means the inverse (false).
+
+## Examples
+
+### Using Sec-CH-UA-WoW64
+
+A server requests the `Sec-CH-UA-WoW64` header by including the {{HTTPHeader("Accept-CH")}} in a _response_ to any request from the client, using the name of the desired header as a token:
+
+```http
+HTTP/1.1 200 OK
+Accept-CH: Sec-CH-UA-WoW64
+```
+
+The client may choose to provide the hint, and add the `Sec-CH-UA-WoW64` header to subsequent requests.
+Adding `Sec-CH-UA-WoW64: ?1` means the user agent's binary is running in 32-bit mode on 64-bit Windows:
+
+```http
+GET /my/page HTTP/1.1
+Host: example.site
+
+Sec-CH-UA-WoW64: ?1
+Sec-CH-UA-Platform: "Windows"
+Sec-CH-UA-Form-Factors: "Desktop"
+```
+
+## Specifications
+
+{{Specifications}}
+
+## Browser compatibility
+
+{{Compat}}
+
+## See also
+
+- [Client hints](/en-US/docs/Web/HTTP/Client_hints)
+- [User-Agent Client Hints API](/en-US/docs/Web/API/User-Agent_Client_Hints_API)
+- {{HTTPHeader("Accept-CH")}}
+- [HTTP Caching: Vary](/en-US/docs/Web/HTTP/Caching#vary) and {{HTTPHeader("Vary")}} header
+- [Improving user privacy and developer experience with User-Agent Client Hints](https://developer.chrome.com/docs/privacy-security/user-agent-client-hints) on developer.chrome.com