This meta tag has no influence on your search engine ranking unless you use it the wrong way. Meta tags who do have a lot of influence are the title of your page, the keywords and the description meta tags.
Title Tag
The title is the first (usually clickable) phrase you see as a search result.
Meta Description Tag
A description of your website in 3 of 4 sentences or Characters are 165.
<meta name=”description” content=”text”>
Keyword Tag
The keywords under which you wish your website to be found.
<meta name=”keywords” content=”text”>
Google Verification Code Tag
The Google Verification Code of our website.
<meta name=”google-site-verification” content=”xxxxxxxxxxxxxxxxxxxxxx”>
Revisiting Code Tag
How often do you want the spiders to come back and index your website again.
<meta name=”revisit-after” content=”periode”>
Meta Robots Tag
How far do you allow robots to spider through your website.
<meta name=”robots” content=”selection”>
Copy Right Tag
<meta name=”copyright” content=”name of owner”>
GoogleBot Tag
You now tell the Googlebot NOT to duplicate the ODP description but the description which is located on your website.
<meta name=”googlebot” content=”code”>
Language Tag
Does your website contains pages in different languages? By adding index pages with different language tags you are able to adjust the language to the specific country.
<meta name=”language” content=”spanish”>
Reply to Email Tag
<meta name=”reply-to” content=”email address”>
Author Tag
<meta name=”web_author” content=”name”>
Http-equiv Tag
<meta http-equiv=”expires” content=”date”>
Rating Tag
You can use one of the following values: general, mature, restricted, 14 years, safe for kids
<meta name=”rating” content=”value”>