Warning
obsoleted
RFC 9111
Registered with IANA and declared by no provider 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 | obsoleted |
|---|---|
| Reference | RFC 9111, Section 5.5: HTTP Caching |