Appendix A. Collected ABNF

This appendix collects all ABNF (Augmented Backus-Naur Form) syntax rules defined throughout this specification. These rules define the syntactic structure of HTTP messages, including methods, status codes, header fields, URIs, and other components.

Description

The ABNF rules in this appendix are listed alphabetically for easy reference. For complete ABNF syntax rules, please refer to the corresponding sections of this specification.

Main syntax rule categories include:

1. HTTP Message Components - Request line, status line, header fields, etc.
2. URIs and Identifiers - URI syntax, authority component, etc.
3. Field Value Syntax - Value formats for various header fields
4. Methods and Status Codes - HTTP methods and response status codes
5. Content Negotiation - Accept, Content-Type, etc.
6. Authentication - Authentication schemes, credential formats, etc.
7. Range and Conditional Requests - Range, If-Match, etc.
8. Date and Time - HTTP date formats

Core Syntax Elements

Core ABNF rules imported from [RFC5234]:

• ALPHA, CR, CRLF, CTL, DIGIT, DQUOTE, HEXDIG, HTAB, LF, OCTET, SP, VCHAR

URI syntax rules imported from [URI]:

• absolute-URI, authority, host, port, query, relative-part, scheme, segment, URI-reference

Note: The complete ABNF rule list contains hundreds of rules. For brevity, this section provides a summary. For detailed ABNF syntax, please refer to Appendix A of RFC 9110 or the relevant sections.