510 Not Extended

Document v1 · published by Koskamo · updated 2026-10-04

HTTP 510 Not Extended is a 5xx server error status code in the IANA HTTP Status Code Registry.

Code: 510
Reason phrase: Not Extended
Registry note: OBSOLETED
Class: 5xx (Server Error)
Defined in: RFC 2774; Status change of HTTP experiments to Historic

Source and provenance

Original source: www.iana.org
Published on Koskamo by: Koskamo
Citation version: Document v1
Reuse: IANA HTTP Status Code Registry (iana.org/assignments/http-status-codes); registry data reproduced verbatim with references

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Published by Koskamo2026-10-04
Version 1