HTTP servers can read the contents of the document head
to generate response headers corresponding to any elements defining a
value for the attribute HTTP-EQUIV.
This provides document authors with a mechanism for identifying
information that should be included in the response headers of an HTTP
request.
HTTP-EQUIV
This attribute binds the element to an HTTP response header.
HTTP header names are not case sensitive. If absent,
the NAME attribute should be used to identify this
meta-information and it should not be used within an HTPP response
header.
Content: Used to supply a value for a named property.
The HTTP-EQUIV attribute can be used in place of the NAME attribute
and has a special significance when documents are retrieved via the
Hypertext Transfer Protocol (HTTP).
META tags with an HTTP-EQUIV attribute are bound to HTTP headers.
Typically, they control the action of browsers, and may be used to
refine the information provided by the actual headers.
HTTP headers are defined in RFC1945 (HTTP/1.0) and
RFC2068 (HTTP/1.1).
HTTP servers may use the property name specified by the HTTP-EQUIV
attribute to create an RFC 822 style header in the HTTP response.
This can't be used to set certain HTTP headers though,
see the HTTP specification for details.
Do not use the META element to define information that should be
associated with an existing HTML element. Example of an inappropriate
use of the META element:
<meta Name = "Title"
Content = "The Physics of Apples">
Do not name an HTTP-EQUIV equal to a response header that should
normally only be generated by the HTTP server. Example names that are
inappropriate include "Server", "Date", and "Last-modified".
Sometimes you may want to 'redirect' a request for one URL, to another.
For example, the original URL has become obsolete and you'd like to
direct the user to another URL.
There's a variety of methods to do this, depending on the situation.
One is:-
Not all browsers support this; Netscape and Microsoft do.
Be sure to place a link in the old document to the new one.
Some browsers will not do the redirect if they are
busy when the specified time arrives, e.g. loading images,
so the delay time needs to be set high enough to allow that the page
has had enough time to load completely. This may require some
experimentation, preferably over a 28.8 Kbaud modem or slower.
Another simple use of client pull is to cause a document to be
automatically reloaded on a regular basis.
<META HTTP-EQUIV = "Refresh"
CONTENT = 1>
<title>Document ONE</title>
<h1>This is Document ONE!</h1>
Here's some text.
I'm often asked: how do you achieve that transition effect when I enter
or leave The WDVL home page
with Microsoft Internet Explorer 4 ?
It's done with META tags:
