Deprecation
IANA permanent
response
RFC 9745
reached by regulation
2 spellings
Declared by 3 providers across 652 published specification files in the APIs.io network.
A count here is providers whose published contract declares this header — not
providers who send it. Response headers set at the edge rarely appear in an OpenAPI at all, so a low
number can measure documentation practice rather than deployment.
Spelled 2 ways
HTTP field names are case-insensitive (RFC 9110 §5.1), so every spelling below is the same header on the wire. A contract is not the wire: generated clients key off the string, and a developer reading two of these sees two different headers.
deprecationDeprecation
Reached by regulation
Basis: evidentiary.
No law names this header; it is the deployed control for an obligation that regulation does impose.
Visible in a published contract, which is what is counted here.
Carried by the http standard.
The registry
| Status | permanent |
|---|---|
| Reference | RFC 9745, Section 2: The Deprecation HTTP Response Header Field |
| Structured type | Item (RFC 9651) |
Providers declaring it (3)
Explore
All headers Versioning & Lifecycle Guidance on headers.apievangelist.com