[ZT] RDP user experience details (cloudflare#23333)

* Update end user exp

Saving changes for end user exp

* Update user identifier formats

SAM and UPN are supported

* adding in known limitations

* adding addtl UPN example

* more examples for SAM

* adding clipboard file formats supported

* adjustments thanks to some feedback!

* edit for clarity

* clipboard support depends on the local program

* fix casing

* Update src/content/docs/cloudflare-one/connections/connect-networks/use-cases/rdp/rdp-browser.mdx

---------

Co-authored-by: Ann Ming Samborski <[email protected]>

Author: 2 people

src/content/docs/cloudflare-one/connections/connect-networks/use-cases/rdp/rdp-browser.mdx

@@ -144,7 +144,7 @@ To connect to a Windows machine over RDP:
 	The App Launcher tile will launch a URL of the form `https://<app-domain>/rdp/<vnet-id>/<target-ip>/<port>`. You may also navigate directly to this URL.
 4. Select the port that you want to connect to. The port selection screen only appears if the Access application allows RDP traffic on multiple ports (for example, port `3389` and port `65321`).
 5. (Optional) In your browser settings, allow the Access application to access the clipboard. Clipboard permissions grant the ability to copy or paste text between the local machine and the remote Windows machine.
-6. Enter your Windows username and password.
+6. Enter your Windows username and password. For more information on supported login credentials, refer to [User identifier formats](#user-identifier-formats).
 
 You now have access to the remote Windows desktop.
 
@@ -174,16 +174,49 @@ Browser-based RDP supports connecting to Windows machines that run the following
 | Other Chromium-based browsers (Opera, Brave) | ✅            |
 | Internet Explorer 11 and below               | ❌            |
 
-### Cloudflare products
+### User identifier formats
 
- <Render file="access/self-hosted-app/product-compatibility" product="cloudflare-one" />
+Browser-based RDP supports connecting to Windows machines using the following login credentials:
 
-## Known limitations
+#### Security Account Manager (SAM)
+
+SAM-formatted user identifiers are supported with and without spaces.
+
+Examples:
+- `DOMAIN\username`
+- `DOMAIN\username with spaces`
+- `.\username`
+- `.\username with spaces`
+- `username`
+- `username with spaces`
+
+<Details header = "Character limits" open= {true}>
+Identifiers which specify a domain, such as `DOMAIN\username`, can have a maximum of 20 characters for the domain and 15 characters for the username.
+
+Identifiers without a domain, such as `.\username`, will use the default domain. The username can have a maximum of 20 characters.
+</Details>
+
+#### User Principal Name (UPN)
 
-Browser-based RDP does not currently support:
+UPN-formatted user identifiers are supported with spaces, with and without quotes.
 
-- TLS certificate verification: Cloudflare uses TLS to connect to the target RDP server but does not verify the origin TLS certificate.
-- [WARP authentication](/cloudflare-one/connections/connect-devices/warp/configure-warp/warp-sessions/#configure-warp-sessions-in-access)
-- Audio over RDP
+Examples:
+- `"username with spaces"@domain.org`
+- `username with [email protected]`
+- `[email protected]`
 
+:::note
+Cloudflare will not configure user identifiers on the RDP target. Any user identifier used to authenticate must be pre-configured on the server.
+:::
+
+### Cloudflare products
+
+ <Render file="access/self-hosted-app/product-compatibility" product="cloudflare-one" />
+
+## Known limitations
 
+- **TLS certificate verification**: Cloudflare uses TLS to connect to the RDP target but does not verify the origin TLS certificate.
+- **WARP authentication**: Users cannot authenticate to RDP targets using their [WARP session identity](/cloudflare-one/connections/connect-devices/warp/configure-warp/warp-sessions/#configure-warp-sessions-in-access).
+- **Audio over RDP**: Users cannot use their microphone and speaker to interact with the remote machine.
+- **Clipboard controls**: Admins do not have the ability to restrict copy/paste actions between the remote machine and the user's local clipboard.
+- **File transfers**: Users cannot copy/paste files from their local machine to the remote machine and vice versa.