2014-02-17 2022-06-08 RFC9111, Section 5.2.4 IETF Review immutable max-age RFC9111, Section 5.2.1.1, 5.2.2.1 max-stale RFC9111, Section 5.2.1.2 min-fresh RFC9111, Section 5.2.1.3 must-revalidate RFC9111, Section 5.2.2.2 must-understand RFC9111, Section 5.2.2.3 no-cache RFC9111, Section 5.2.1.4, 5.2.2.4 no-store RFC9111, Section 5.2.1.5, 5.2.2.5 no-transform RFC9111, Section 5.2.1.6, 5.2.2.6 only-if-cached RFC9111, Section 5.2.1.7 private RFC9111, Section 5.2.2.7 proxy-revalidate RFC9111, Section 5.2.2.8 public RFC9111, Section 5.2.2.9 s-maxage RFC9111, Section 5.2.2.10 stale-if-error RFC5861, Section 4 stale-while-revalidate RFC5861, Section 3