Age
IANA permanent
response
RFC 9111
Declared by 1 provider across 21 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.
The registry
| Status | permanent |
|---|---|
| Reference | RFC 9111, Section 5.1: HTTP Caching |