Is there a lt;meta gt; tag to turn off caching in all browsers? The list is just examples of different techniques, it's not for direct insertion If copied, the second would overwrite the first and the fourth would overwrite the third because of the http-equiv declarations AND fail with the W3C validator At most, one could have one of each http-equiv declarations; pragma, cache-control and expires
How to set HTTP headers (for cache-control)? - Stack Overflow @FélixGagnon-Grenier "The http-equiv attribute is an enumerated attribute" means it allows only values in the table in the spec It even calls out caching in the later section ("other pragma directives"): > Pragma directives corresponding to headers that affect the HTTP processing model (e g caching) must not be registered, as they would result in HTTP-level behavior being different for user
Difference between Pragma and Cache-Control headers? Pragma is the HTTP 1 0 implementation and cache-control is the HTTP 1 1 implementation of the same concept They both are meant to prevent the client from caching the response Older clients may not support HTTP 1 1 which is why that header is still in use