Web / Authoring / HTML / meta
Back to Basics: META Tags by Scott Clark
With all the new HTML tags that are coming out, it's easy to overlook some of the greatest tools in our arsenal of HTML tricks. There are still a few HTML goodies lying around that'll help you keep your pages more up to date, make them easier to find, and even stop them from becoming framed. What's more, some of these tags have been with us since the first Web browsers were released.
META tags can be very useful for Web developers. They can be used to identify the creator of the page, what HTML specs the page follows, the keywords and description of the page, and the refresh parameter (which can be used to cause the page to reload itself, or to load another page). And these are just a few of the common uses!
First, there are two types of META tags: HTTP-EQUIV and META tags with a NAME attribute.
META HTTP-EQUIV tags are the equivalent of HTTP headers. To understand what headers are, you need to know a little about what actually goes on when you use your Web browser to request a document from a Web server. When you click on a link for a page, the Web server receives your browser's request via HTTP. Once the Web server has made sure that the page you've requested is indeed there, it generates an HTTP response. The initial data in that response is called the "HTTP header block." The header tells the Web browser information which may be useful for displaying this particular document
Back to META tags. Just like normal headers, META HTTP-EQUIV tags usually control or direct the actions of Web browsers, and are used to further refine the information which is provided by the actual headers. HTTP-EQUIV tags are designed to affect the Web browser in the same manner as normal headers. Certain Web servers may translate META HTTP-EQUIV tags into actual HTTP headers automatically so that the user's Web browser would simply see them as normal headers. Some Web servers, such as Apache and CERN httpd, use a separate text file which contains meta-data. A few Web server-generated headers, such as "Date," may not be overwritten by META tags, but most will work just fine with a standard Web server.
META tags with a NAME attribute are used for META types which do not correspond to normal HTTP headers. This is still a matter of disagreement among developers, as some search engine agents (worms and robots) interpret tags which contain the keyword attribute whether they are declared as "name" or "http-equiv," adding fuel to the fires of confusion
Comments are welcome
Originally written on WebDeveloper.com in October 1997. Revised: May 17, 2000