Gated-execute on Twelve HTTP status codes, by the book

Perfect! I now have all the information needed. Let me compile the final answer with the exact quotes and sections from RFC 9110.

Based on my research of RFC 9110 (HTTP Semantics), here's the comprehensive information for each status code:

From Section 15.1 of RFC 9110, the specification explicitly lists which status codes are heuristically cacheable: "200, 203, 204, 206, 300, 301, 308, 404, 405, 410, 414, and 501".

I've verified each status code in its respective section:

• 203, 206, 308, 405, 410, 414, 501 each have explicit statements saying they are "heuristically cacheable"
• 303, 307, 413, 421, 422 do not have such explicit statements and are not in the overview list, so they are not heuristically cacheable

{"answers":[{"code":"203","reason":"Non-Authoritative Information","section":"15.3.4","heuristicallyCacheable":true,"quote":"A 203 response is heuristically cacheable; i.e., unless otherwise indicated by the method definition or explicit cache controls (see Section 4.2.2 of [CACHING]).","url":"https://www.rfc-editor.org/rfc/rfc9110.html"},{"code":"206","reason":"Partial Content","section":"15.3.7","heuristicallyCacheable":true,"quote":"A 206 response is heuristically cacheable; i.e., unless otherwise indicated by explicit cache controls (see Section 4.2.2 of [CACHING]).","url":"https://www.rfc-editor.org/rfc/rfc9110.html"},{"code":"303","reason":"See Other","section":"15.4.4","heuristicallyCacheable":false,"quote":"The 303 (See Other) status code indicates that the server is redirecting the user agent to a different resource, as indicated by a URI in the Location header field.","url":"https://www.rfc-editor.org/rfc/rfc9110.html"},{"code":"307","reason":"Temporary Redirect","section":"15.4.8","heuristicallyCacheable":false,"quote":"The 307 (Temporary Redirect) status code indicates that the target resource resides temporarily under a different URI and the user agent MUST NOT change the request method.","url":"https://www.rfc-editor.org/rfc/rfc9110.html"},{"code":"308","reason":"Permanent Redirect","section":"15.4.9","heuristicallyCacheable":true,"quote":"A 308 response is heuristically cacheable; i.e., unless otherwise indicated by the method definition or explicit cache controls (see Section 4.2.2 of [CACHING]).","url":"https://www.rfc-editor.org/rfc/rfc9110.html"},{"code":"405","reason":"Method Not Allowed","section":"15.5.6","heuristicallyCacheable":true,"quote":"A 405 response is heuristically cacheable; i.e., unless otherwise indicated by the method definition or explicit cache controls (see Section 4.2.2 of [CACHING]).","url":"https://www.rfc-editor.org/rfc/rfc9110.html"},{"code":"410","reason":"Gone","section":"15.5.11","heuristicallyCacheable":true,"quote":"A 410 response is heuristically cacheable; i.e., unless otherwise indicated by the method definition or explicit cache controls (see Section 4.2.2 of [CACHING]).","url":"https://www.rfc-editor.org/rfc/rfc9110.html"},{"code":"413","reason":"Content Too Large","section":"15.5.14","heuristicallyCacheable":false,"quote":"The 413 (Content Too Large) status code indicates that the server is refusing to process a request because the request content is larger than the server is willing.","url":"https://www.rfc-editor.org/rfc/rfc9110.html"},{"code":"414","reason":"URI Too Long","section":"15.5.15","heuristicallyCacheable":true,"quote":"A 414 response is heuristically cacheable; i.e., unless otherwise indicated by the method definition or explicit cache controls (see Section 4.2.2 of [CACHING]).","url":"https://www.rfc-editor.org/rfc/rfc9110.html"},{"code":"421","reason":"Misdirected Request","section":"15.5.20","heuristicallyCacheable":false,"quote":"The 421 (Misdirected Request) status code indicates that the request was directed at a server that is unable or unwilling to produce an authoritative response.","url":"https://www.rfc-editor.org/rfc/rfc9110.html"},{"code":"422","reason":"Unprocessable Content","section":"15.5.21","heuristicallyCacheable":false,"quote":"The 422 (Unprocessable Content) status code indicates that the server understands the content type of the request content (hence a 415 (Unsupported Media Type)).","url":"https://www.rfc-editor.org/rfc/rfc9110.html"},{"code":"501","reason":"Not Implemented","section":"15.6.2","heuristicallyCacheable":true,"quote":"A 501 response is heuristically cacheable; i.e., unless otherwise indicated by the method definition or explicit cache controls (see Section 4.2.2 of [CACHING]).","url":"https://www.rfc-editor.org/rfc/rfc9110.html"}]}