no-vary: mention Cache-Control

[nidhijaju]

@reschke said:

Speaking of which, RFC 9111 states in
https://greenbytes.de/tech/specs/rfc9111.html#rfc.section.4.p.3:

Note that a cache extension can override any of the requirements
listed; see Section 5.2.3.

which is about Cache-Control.

Was it ever considered to use Cache-Control here? (yes, I understand the
parsing issues) ... in any case, a short statement why not might be good.

Also: maybe make it clear upfront that the spec really defines a "Cache
Extension", as described in Section 4 of RFC 9111 (and use that in
Section 7, which brought me here...)

(let me know if I should suggest text)

(See https://lists.w3.org/Archives/Public/ietf-http-wg/2025OctDec/0051.html)

[nidhijaju]

@reschke, if you have some text you'd like to propose here to briefly outline the issues with Cache-Control, that would be super helpful!