I think there are two related issues here:
Any time you are saying HTTP-EQUIV you are saying the Content should
conform to the syntax of an HTTP header (and there is an Expires: header).
Servers are free to ignore META tags and not put the information out as
HTTP headers, or to ignore information that conflicts with other
server-generated headers. I'm not sure what servers, if any, do parse the
META tags and generate HTTP headers, though I know some robots read them
directly from the HTML.
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Albert Lunde [email protected]