HTTP status codes and reason phrases
Status codes from the following RFCs are all observed:
* RFC 9110: HTTP Semantics, obsoletes 7231, which obsoleted 2616
* RFC 6585: Additional HTTP Status Codes
* RFC 3229: Delta encoding in HTTP
* RFC 4918: HTTP Extensions for WebDAV, obsoletes 2518
* RFC 5842: Binding Extensions to WebDAV
* RFC 7238: Permanent Redirect
* RFC 2295: Transparent Content Negotiation in HTTP
* RFC 2774: An HTTP Extension Framework
* RFC 7725: An HTTP Status Code to Report Legal Obstacles
* RFC 7540: Hypertext Transfer Protocol Version 2 (HTTP/2)
* RFC 2324: Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0)
* RFC 8297: An HTTP Status Code for Indicating Hints
* RFC 8470: Using Early Data in HTTP