On Tue, 12 Jul 2005, Richard Gration wrote:
REFRESH (or "Refresh:") is a HTTP header.
Well, only in as much as the applicable HTTP RFC (2616) allows
arbitrary HTTP headers to be added, even though they're not defined in
the RFC.
Last time I tested, IE doesn't support this HTTP "header". It only
supports the substitute meta. Quaint, really.
The META tag is a way to allow pages to specify values for some HTTP
headers.
I'm afraid that's very misleading. I know of very few web servers
which parse HTML and turn the resulting meta items into real HTTP
headers. And in this case it's far from clear that it would really do
anything constructive.
OK, I admit that *was* originally the intention of meta, but it seems
to have quickly dropped out of the plan, many years ago now. If you
want a server to produce HTTP headers, I'd have to recommend reading
its instructions to find out how to ask it to produce real HTTP
headers (Apache has a number of versatile options for this).
I might add that HTTP headers are something that make good sense with
all kinds of content, such as images, PDF files, plain text, etc.
etc., and are by no means limited to HTML, whereas meta is defined
only for (x)html.
Nowadays, if anything is going to pay attention to meta in HTML, it's
likely to be the client agent. But meantime the other participants in
the web transaction (proxies, web caches etc.) will typically be
disregarding the meta inside the HTML, and honouring only the real
HTTP headers, which can produce a really confusing mess for anyone who
seriously thinks that sticking in a meta is any real substitute for a
real HTTP header.
no offence intended.