What's this "META" tag I keep hearing about?

The official HTML RFC1866 is particularly unhelpful on this tag, describing it as "Associated meta-information".

One of the most useful versions of the META tag should be HTTP-EQUIV. Whenever a web server serves out a file, it first adds a few header lines, including, for example, a line telling the browser what sort (mime type) of file is coming. It is these header lines that tell a browser how to deal with the file it receives. (If for example a server hasn't been told to treat files with an htm extension (and not just html extensions) as being HTML files, your browser will read them as text files and you'll see all the tags!). In principle, the HTTP-EQUIV attribute should either cause the server to add a header line or cause the browser to read it as if a header line had been added. In practice I'm not sure whether it does and the specification (para 5.25) says that the method by which meta-information is extracted is "unspecified and not mandatory".

Another use is offered by the various search engines. Both Alta Vista and Infoseek suggest the use of tags for keyword searching and descriptions rather than their automatic indexing. Thus you might include in the head section of your page:

<META NAME="description" CONTENT="The description you want">
<META NAME="keywords" CONTENT="The keywords you want searches to pick up">

The Netscape browser also recognises an HTTP-EQUIV function of REFRESH, which can be used to load a new page a particular time after loading the first page or (if the URL argument is a sound file) to play music once the page is loaded. If for example you have an introduction page at http://www1.url/intro.html and a second page at http://www2.url/page_2.html, you might include in the head section of the page at http://www1.url/intro.html a line:

<META HTTP-EQUIV="REFRESH" CONTENT="10; URL=http://www2.url/page_2.html">

This will send the Netscape browser to http://www2.url/page_2.html ten seconds after accessing http://www1.url/intro.html.

For more information on the META tag see

• the META page of the HTML Documentation Collection of the Information Commons at the University of Toronto
• Sandia's META section
• Dr. Clue's HTML/CGI Guide
• or Netscape's Push-Pull page