META Tag Information

META tag use in HTML documents have numerous uses, including identifying who created a page, what specs it follows, the keywords for a page, and the description of a page.
Here is a complete list of META tags and their uses:

HTTP-EQUIV TAGS

Expires

Pragma

Content-Type

Content-Language

Refresh

Window-target

Ext-cache

Set-Cookie

PICS-Label

Cache-Control

Vary

Lotus

NAME ATTRIBUTES

Robots

Description

Keywords

Author

Generator

Formatter

Classification

Rating

VW96.ObjectType

Dublin Core

HTML 4.0

HTdig

HTdig notification

Other NAME attributes are useful for specific in-house applications.
META tags should always be placed in the head of the HTML document between the HEAD tags, before the BODY tag. This is very important with framed pages, as a lot of developers tend to forget to include them on individual framed pages.

Expires: This tells the browser the date and time when the document will be considered "expired." If a user is using Netscape Navigator, a request for a document whose time has "expired" will initiate a new network request. An illegal Expires date, (such as "0"), is interpreted by the browser as "expires immediately." Dates must be given in the RFC850 format, with a GMT time zone:

Pragma: This is another way to control browser caching. To use this tag, the value must be "no-cache." When this is included in a document, this prevents Netscape Navigator from caching a page locally.

Refresh: This tag specifies a delay in seconds before the Web browser reloads the document automatically. It can also specify an alternative URL for the browser to load, causing one page to switch to another (often used for a "forwarding address").

Remember to place quotation marks around the CONTENT attribute, or your page will be stuck in the mud.

Set-Cookie: This is yet another method of setting a cookie in the Web browser. if you use an expiration date, the cookie is considered permanent and will be saved to disk; otherwise, it will be considered valid only for the current session and will be erased upon closing the browser.

Window-target: This one specifies the "named window" of the current page, and can be used to prevent a page from appearing inside another framed page.