18. IANA Considerations
The change controller for the following registrations is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".
18.1. URI Scheme Registration
IANA has updated the "Uniform Resource Identifier (URI) Schemes"
registry [BCP35] at
18.2. Method Registration
IANA has updated the "Hypertext Transfer Protocol (HTTP) Method
Registry" at
+=========+======+============+=========+ | Method | Safe | Idempotent | Section | +=========+======+============+=========+ | CONNECT | no | no | 9.3.6 | +---------+------+------------+---------+ | DELETE | no | yes | 9.3.5 | +---------+------+------------+---------+ | GET | yes | yes | 9.3.1 | +---------+------+------------+---------+ | HEAD | yes | yes | 9.3.2 | +---------+------+------------+---------+ | OPTIONS | yes | yes | 9.3.7 | +---------+------+------------+---------+ | POST | no | no | 9.3.3 | +---------+------+------------+---------+ | PUT | no | yes | 9.3.4 | +---------+------+------------+---------+ | TRACE | yes | yes | 9.3.8 | +---------+------+------------+---------+ | * | no | no | 18.2 | +---------+------+------------+---------+
Table 7
The method name "*" is reserved because using "*" as a method name would conflict with its usage as a wildcard in some fields (e.g., "Access-Control-Request-Method").
18.3. Status Code Registration
IANA has updated the "Hypertext Transfer Protocol (HTTP) Status Code
Registry" at
+=======+===============================+=========+ | Value | Description | Section | +=======+===============================+=========+ | 100 | Continue | 15.2.1 | +-------+-------------------------------+---------+ | 101 | Switching Protocols | 15.2.2 | +-------+-------------------------------+---------+ | 200 | OK | 15.3.1 | +-------+-------------------------------+---------+ | 201 | Created | 15.3.2 | +-------+-------------------------------+---------+ | 202 | Accepted | 15.3.3 | +-------+-------------------------------+---------+ | 203 | Non-Authoritative Information | 15.3.4 | +-------+-------------------------------+---------+ | 204 | No Content | 15.3.5 | +-------+-------------------------------+---------+ | 205 | Reset Content | 15.3.6 | +-------+-------------------------------+---------+ | 206 | Partial Content | 15.3.7 | +-------+-------------------------------+---------+ | 300 | Multiple Choices | 15.4.1 | +-------+-------------------------------+---------+ | 301 | Moved Permanently | 15.4.2 | +-------+-------------------------------+---------+ | 302 | Found | 15.4.3 | +-------+-------------------------------+---------+ | 303 | See Other | 15.4.4 | +-------+-------------------------------+---------+ | 304 | Not Modified | 15.4.5 | +-------+-------------------------------+---------+ | 305 | Use Proxy | 15.4.6 | +-------+-------------------------------+---------+ | 306 | (Unused) | 15.4.7 | +-------+-------------------------------+---------+ | 307 | Temporary Redirect | 15.4.8 | +-------+-------------------------------+---------+ | 308 | Permanent Redirect | 15.4.9 | +-------+-------------------------------+---------+ | 400 | Bad Request | 15.5.1 | +-------+-------------------------------+---------+ | 401 | Unauthorized | 15.5.2 | +-------+-------------------------------+---------+ | 402 | Payment Required | 15.5.3 | +-------+-------------------------------+---------+ | 403 | Forbidden | 15.5.4 | +-------+-------------------------------+---------+ | 404 | Not Found | 15.5.5 | +-------+-------------------------------+---------+ | 405 | Method Not Allowed | 15.5.6 | +-------+-------------------------------+---------+ | 406 | Not Acceptable | 15.5.7 | +-------+-------------------------------+---------+ | 407 | Proxy Authentication Required | 15.5.8 | +-------+-------------------------------+---------+ | 408 | Request Timeout | 15.5.9 | +-------+-------------------------------+---------+ | 409 | Conflict | 15.5.10 | +-------+-------------------------------+---------+ | 410 | Gone | 15.5.11 | +-------+-------------------------------+---------+ | 411 | Length Required | 15.5.12 | +-------+-------------------------------+---------+ | 412 | Precondition Failed | 15.5.13 | +-------+-------------------------------+---------+ | 413 | Content Too Large | 15.5.14 | +-------+-------------------------------+---------+ | 414 | URI Too Long | 15.5.15 | +-------+-------------------------------+---------+ | 415 | Unsupported Media Type | 15.5.16 | +-------+-------------------------------+---------+ | 416 | Range Not Satisfiable | 15.5.17 | +-------+-------------------------------+---------+ | 417 | Expectation Failed | 15.5.18 | +-------+-------------------------------+---------+ | 418 | (Unused) | 15.5.19 | +-------+-------------------------------+---------+ | 421 | Misdirected Request | 15.5.20 | +-------+-------------------------------+---------+ | 422 | Unprocessable Content | 15.5.21 | +-------+-------------------------------+---------+ | 426 | Upgrade Required | 15.5.22 | +-------+-------------------------------+---------+ | 500 | Internal Server Error | 15.6.1 | +-------+-------------------------------+---------+ | 501 | Not Implemented | 15.6.2 | +-------+-------------------------------+---------+ | 502 | Bad Gateway | 15.6.3 | +-------+-------------------------------+---------+ | 503 | Service Unavailable | 15.6.4 | +-------+-------------------------------+---------+ | 504 | Gateway Timeout | 15.6.5 | +-------+-------------------------------+---------+ | 505 | HTTP Version Not Supported | 15.6.6 | +-------+-------------------------------+---------+
Table 8
18.4. Field Name Registration
This specification updates the HTTP-related aspects of the existing registration procedures for message header fields defined in [RFC3864]. It replaces the old procedures as they relate to HTTP by defining a new registration procedure and moving HTTP field definitions into a separate registry.
IANA has created a new registry titled "Hypertext Transfer Protocol (HTTP) Field Name Registry" as outlined in Section 16.3.1.
IANA has moved all entries in the "Permanent Message Header Field
Names" and "Provisional Message Header Field Names" registries (see
1. The 'Applicable Protocol' field has been omitted.
2. Entries that had a status of 'standard', 'experimental', 'reserved', or 'informational' have been made to have a status of 'permanent'.
3. Provisional entries without a status have been made to have a status of 'provisional'.
4. Permanent entries without a status (after confirmation that the registration document did not define one) have been made to have a status of 'provisional'. The expert(s) can choose to update the entries' status if there is evidence that another is more appropriate.
IANA has annotated the "Permanent Message Header Field Names" and "Provisional Message Header Field Names" registries with the following note to indicate that HTTP field name registrations have moved:
| *Note* | | HTTP field name registrations have been moved to | [https://www.iana.org/assignments/http-fields] per [RFC9110].
IANA has updated the "Hypertext Transfer Protocol (HTTP) Field Name Registry" with the field names listed in the following table.
+===========================+============+=========+============+ | Field Name | Status | Section | Comments | +===========================+============+=========+============+ | Accept | permanent | 12.5.1 | | +---------------------------+------------+---------+------------+ | Accept-Charset | deprecated | 12.5.2 | | +---------------------------+------------+---------+------------+ | Accept-Encoding | permanent | 12.5.3 | | +---------------------------+------------+---------+------------+ | Accept-Language | permanent | 12.5.4 | | +---------------------------+------------+---------+------------+ | Accept-Ranges | permanent | 14.3 | | +---------------------------+------------+---------+------------+ | Allow | permanent | 10.2.1 | | +---------------------------+------------+---------+------------+ | Authentication-Info | permanent | 11.6.3 | | +---------------------------+------------+---------+------------+ | Authorization | permanent | 11.6.2 | | +---------------------------+------------+---------+------------+ | Connection | permanent | 7.6.1 | | +---------------------------+------------+---------+------------+ | Content-Encoding | permanent | 8.4 | | +---------------------------+------------+---------+------------+ | Content-Language | permanent | 8.5 | | +---------------------------+------------+---------+------------+ | Content-Length | permanent | 8.6 | | +---------------------------+------------+---------+------------+ | Content-Location | permanent | 8.7 | | +---------------------------+------------+---------+------------+ | Content-Range | permanent | 14.4 | | +---------------------------+------------+---------+------------+ | Content-Type | permanent | 8.3 | | +---------------------------+------------+---------+------------+ | Date | permanent | 6.6.1 | | +---------------------------+------------+---------+------------+ | ETag | permanent | 8.8.3 | | +---------------------------+------------+---------+------------+ | Expect | permanent | 10.1.1 | | +---------------------------+------------+---------+------------+ | From | permanent | 10.1.2 | | +---------------------------+------------+---------+------------+ | Host | permanent | 7.2 | | +---------------------------+------------+---------+------------+ | If-Match | permanent | 13.1.1 | | +---------------------------+------------+---------+------------+ | If-Modified-Since | permanent | 13.1.3 | | +---------------------------+------------+---------+------------+ | If-None-Match | permanent | 13.1.2 | | +---------------------------+------------+---------+------------+ | If-Range | permanent | 13.1.5 | | +---------------------------+------------+---------+------------+ | If-Unmodified-Since | permanent | 13.1.4 | | +---------------------------+------------+---------+------------+ | Last-Modified | permanent | 8.8.2 | | +---------------------------+------------+---------+------------+ | Location | permanent | 10.2.2 | | +---------------------------+------------+---------+------------+ | Max-Forwards | permanent | 7.6.2 | | +---------------------------+------------+---------+------------+ | Proxy-Authenticate | permanent | 11.7.1 | | +---------------------------+------------+---------+------------+ | Proxy-Authentication-Info | permanent | 11.7.3 | | +---------------------------+------------+---------+------------+ | Proxy-Authorization | permanent | 11.7.2 | | +---------------------------+------------+---------+------------+ | Range | permanent | 14.2 | | +---------------------------+------------+---------+------------+ | Referer | permanent | 10.1.3 | | +---------------------------+------------+---------+------------+ | Retry-After | permanent | 10.2.3 | | +---------------------------+------------+---------+------------+ | Server | permanent | 10.2.4 | | +---------------------------+------------+---------+------------+ | TE | permanent | 10.1.4 | | +---------------------------+------------+---------+------------+ | Trailer | permanent | 6.6.2 | | +---------------------------+------------+---------+------------+ | Upgrade | permanent | 7.8 | | +---------------------------+------------+---------+------------+ | User-Agent | permanent | 10.1.5 | | +---------------------------+------------+---------+------------+ | Vary | permanent | 12.5.5 | | +---------------------------+------------+---------+------------+ | Via | permanent | 7.6.3 | | +---------------------------+------------+---------+------------+ | WWW-Authenticate | permanent | 11.6.1 | | +---------------------------+------------+---------+------------+ | * | permanent | 12.5.5 | (reserved) | +---------------------------+------------+---------+------------+
Table 9
The field name "*" is reserved because using that name as an HTTP header field might conflict with its special semantics in the Vary header field (Section 12.5.5).
IANA has updated the "Content-MD5" entry in the new registry to have a status of 'obsoleted' with references to Section 14.15 of [RFC2616] (for the definition of the header field) and Appendix B of [RFC7231] (which removed the field definition from the updated specification).
18.5. Authentication Scheme Registration
IANA has updated the "Hypertext Transfer Protocol (HTTP)
Authentication Scheme Registry" at
18.6. Content Coding Registration
IANA has updated the "HTTP Content Coding Registry" at
+============+===========================================+=========+ | Name | Description | Section | +============+===========================================+=========+ | compress | UNIX "compress" data format [Welch] | 8.4.1.1 | +------------+-------------------------------------------+---------+ | deflate | "deflate" compressed data ([RFC1951]) | 8.4.1.2 | | | inside the "zlib" data format ([RFC1950]) | | +------------+-------------------------------------------+---------+ | gzip | GZIP file format [RFC1952] | 8.4.1.3 | +------------+-------------------------------------------+---------+ | identity | Reserved | 12.5.3 | +------------+-------------------------------------------+---------+ | x-compress | Deprecated (alias for compress) | 8.4.1.1 | +------------+-------------------------------------------+---------+ | x-gzip | Deprecated (alias for gzip) | 8.4.1.3 | +------------+-------------------------------------------+---------+
Table 10
18.7. Range Unit Registration
IANA has updated the "HTTP Range Unit Registry" at
+=================+==================================+=========+ | Range Unit Name | Description | Section | +=================+==================================+=========+ | bytes | a range of octets | 14.1.2 | +-----------------+----------------------------------+---------+ | none | reserved as keyword to indicate | 14.3 | | | range requests are not supported | | +-----------------+----------------------------------+---------+
Table 11
18.8. Media Type Registration
IANA has updated the "Media Types" registry at
IANA has updated the registry note about "q" parameters with a link to Section 12.5.1 of this document.
18.9. Port Registration
IANA has updated the "Service Name and Transport Protocol Port Number
Registry" at
1. use this document as "Reference", and
2. when currently unspecified, set "Assignee" to "IESG" and "Contact" to "IETF_Chair".
18.10. Upgrade Token Registration
IANA has updated the "Hypertext Transfer Protocol (HTTP) Upgrade
Token Registry" at
+======+===================+=========================+=========+ | Name | Description | Expected Version Tokens | Section | +======+===================+=========================+=========+ | HTTP | Hypertext | any DIGIT.DIGIT (e.g., | 2.5 | | | Transfer Protocol | "2.0") | | +------+-------------------+-------------------------+---------+
Table 12
19. References