Content-Type
The HTTP content type may be extended to give the character set.
Used to identify which alphabetical character set the browser should load.

<META http-equiv="content-type" content="text/html; charset=iso-8859-1">

Robot Instructions - Individual page instruction to search engines
(use robot.txt file to exclude directories and files)

<META name="robots" content="index,follow">

   index    - List page in search engine
   noindex - Do not list page in search engine
   follow   - Follow links on this page and include in Index
   nofollow- Do not follow links on this page nor include in Index

Description
A summary of what is contained in your webpage/website. Search engines will display a maximum of 200 characters (approximately 25 words) of information.

<META Name="description" Content="Wits-End, a site by Webmasters for Webmasters. Offering news, advice, techniques, and links to the best spots on the WEB.">

Keywords
Words used by people to search for content.
You can have up to 1000 characters (approximately 150 words) of information (spearated by a comma) - although some search engines accept only 300-500 characters.

Do not repeat words used in the title or in the description tag. (most search engines will omit sites that use the same word more than 3 times)

<META Name="keywords" Content="webmaster, news, web, travel, books, links">

Author
Clearly identifies who is the author and/or the responsible party for making updates to the webpage(s).
Supported data formats include the name, email address of the webmaster, company name or Internet address (URL). The most common format is to insert the name of the person or organization and a contact email address

"meta name="author" content="Joann Chokrach (webmaster@wits-end.com)">

Copyright
Copyright statement for document

"meta name="copyright" content="Copyright 1995-2001 The Wits">

LINK
Used to indicate relationships between documents. There are two types:
REL (normal relationship) and REV (reverse relationship)

REV="made"
Indicates the creator of the document. Usually the URL is a mailto: URL with the creator's e-mail address.
<link rev=made href="mailto:webmaster@wits-end.com">

REL="stylesheet"
Indicates the location of the appropriate style sheet for the current document. <link rel="stylesheet" href="stylesheet.css">

No Cache
Directs browsers and Proxy servers not to cache files for reuse.

<META http-equiv="Pragma" content="no-cache">

PICS-Label (3rd party Site Rating)
To identify site content to Proxy servers that filter content to their users (such as major corporations, on-line services and child protection software).

Go to the Internet Content Rating Association to register your site

<META http-equiv="PICS-Label" content='(    )'>

Redirect:
A script that automatically redirects you to a different page. (use absolute URL)
Avoid using a redirect on your home page.
<META http-equiv="refresh" Content=".5;http://wwww.domain.com/dir/pagename.htm">

Refresh Page
Update the page at the specified interval - measured in seconds
(the example below is set for every 15 minutes)

<META http-equiv="refresh" content="900">

Revisit-After
Specifies how many often the search engine should revisit your webpage - in days.
(X represents the number of days)

<META name="Revisit-After" content="X Days">

Window-Target
Specifies thenamed window for the current page, and can be used to prevent a page from appearing inside another framed page. The Web browser will force the page to go the top frameset.

<META HTTP-EQUIV="Window-target" CONTENT="_top">