Robots metatag

Robots: <meta name="robots" content="index,follow">

Many web pages have this tag wrong. An example of the wrong usage is content="index, follow, all" - wrong because some spiders can't handle spaces between the words in the tag or the word "all". Most engines by default assume that you want a web page to be indexed and links followed, so using the wrong syntax can actually result in the spider coming to the wrong conclusion and penalizing, or worse, ignoring the page outright.

If by chance you do not want your links followed, or the page not indexed, then you would substitute "noindex" and or "nofollow" into the tag. You can also make an inline link no-follow with the following code:
<a href="http://www.site.com/page.html" rel="nofollow">Visit My Page</a>

revisit-after
<meta name="revisit-after" content="7 days">

rating content
<meta name="rating" content="General">

distribution
<meta name="distribution" content="Global">

classification
<meta name="classification" content="PRIMARY KEYWORD PHRASE">

author
<meta name="author" content="Company Name">

copyright
<meta name="copyright" content="Company Name © 2010">

cache-control
<meta name="cache-control" content="Public">