510 Not Extended (OBSOLETED)

HTTP status code 510 Not Extended (OBSOLETED). Defined in RFC2774.

http-status kind status-code status standard verification verified tier A iana-registry-row@1

registry record

value: 510

references: RFC2774

Value	510
Description	Not Extended (OBSOLETED)
Reference	[RFC2774][Status change of HTTP experiments to Historic]

source: https://www.iana.org/assignments/http-status-codes/http-status-codes-1.csv
version: IANA registry, Last-Modified: Fri, 24 Oct 2025 07:01:38 GMT
retrieved: 2026-05-29 · updated: 2026-05-29

agent: curl -H 'accept: application/json' wire.phall.io/http-status/510 or /http-status/510.json