Here is a brief outline of some of the other meta tags other than keyword and descriptions. We’ve learned how meta keywords and description tags remain viable, however, less important when it comes to ranking web sites today compared to the past. The leaves all the rest of the meta tags to discuss, and quite frankly, one doesn’t need to mention anymore.
A number of web page builders will automatically implement a slew of meta tags, the majority, if not all, are unnecessary. Here is a list of meta items that should remain on your website.
The title tag remains the most important and should be placed before the opening ‘body’ tag and right after the meta tags. The maximum character length of the title tag should be 63. If you question the character maximums just do a quick search and count yourself.
Of all the garbage metas that web builders pump out only three are needed (apart from the title tag). Here is a list of what should be included between your ‘head’ tags.
1) Declare a doc type. Not really for SEO purposes exclusively but a part of the current W3C web standards. It’s good to create web pages that validate. If you don’t know if your page validates submit it here: HTML Validator.
2) meta http-equiv=“Content-Type” content=“text/html; charset=iso-8859-1” <-- declare a character set, this helps the browser display your page, especially important if you're using funny characters (other languages.)
3) Meta description tag 156 characters, it sounds small but again, count for yourself in Google if you don’t believe it. Put power words and keywords in your description tag. Remember, include this tag when your content can’t reflect (or ODP description) your web page well. Don’t stuff with keywords, spam with unrelated content, or fatten with too many words.
4) Meta keyword tag, max 3-5 keyword phrases and 256 characters. I would keep this tag under 200. But frankly folks, faced with the new environment in 2008 I would delete this tag all together.
If you consider these elements, remembering again that the title tag remains the most important of all, then you’re off to a good start when building optimized web pages.