Keep compatibility with HTTP Cache Groups RFC !

[kapouer]

https://datatracker.ietf.org/doc/draft-ietf-httpbis-cache-groups/

Also: That would be the right header, and there is already a somewhat long list of directives https://developer.mozilla.org/fr/docs/Web/HTTP/Headers/Cache-Control

Cache-Control: max-age=3600, tag=A;B;C, lock=permA;permB, map=/url, ...