META Tags are HTML code tags inserted into the “head” area of your web pages that describe the content of a webpage and (sometimes) provide instructions to visiting search engine spiders and browsers. Essentially, META tag information is used to communicate information that a human visitor is likely not concerned with. Below I will discuss the most common and recommended META tags.
META Name: Abstract
<META name="Abstract" content="Abstract phrase" />
The Abstract META tag is similar to the description Meta tag, except it is an abstraction or a brief summary of the description META tag. Generally the abstract tag is a one line sentence which gives an overview of the entire webpage. Search engines don’t use this tag as often as the description tag but it is still worth including.
META Name: Description
<META name="Description" content="Your description" />
Many search engines display the contents of the Description META tag along with your title in their results. You should keep in mind that a search engine limits the length of description it displays. Thus, when creating your description, you should write the first sentence (ideally 20 words or less) in a way that will capture the attention of a user and use the rest of the description tag to elaborate further. I have read conflicting things about how long the description tag should be but a consensus seems to be 200-250 characters.
One useful thing to note is that instead of using your description tag, some search engines (like Google) will use the description found on the Open Directory Project. See the robots tag description below for a way to prevent this from happening.
META Name: Keyword
<META name="Keywords" content="keyword1, keyword2, keyword3, etc." />
Keywords are sometimes used by some search engines (actually not very many these days) as a means to categorize your website based on its indexing algorithm. Make sure you choose keywords that are relevant to your site and avoid repetition as some search engines will penalize your rankings. Like the description tag, search engines give priority to the first few words in your description, so focus on your main keywords first and then move on to secondary or other related words. While I haven’t seen a definitive statement, I have read that search engines that use the keyword tag will generally index up to 1000 characters and that commas are not required. Note: when creating keywords for your website, do not infringe on other companies’ trademarks or copyrights.
META Name: HTTP-EQUIV
<META name="Content-Type" content=" text/html; charset=utf-8" />
META tags with an HTTP-EQUIV attribute are equivalent to HTTP headers. Typically, they control the action of browsers. Generally, you won’t care about these or what the preceding sentence actually means. There is one tag of this type however, that is useful, namely the Content-Type, which tells the browser which character set to use. This is obviously most useful if your page is written in or contains pages written in languages that require unique characters. For basic English pages, use a charset of ISO-8859-1 or UTF-8.
Other HTTP-EQUIV META tags to possibly investigate are Expires (date and time after which the document should be considered expired), Pragma (mostly used to prevent browser caching)
META Name: Revisit
<META name="Revisit-After" content="X Days" />
The Revisit tag tells a search engine or spider how often it should come to your website for re-indexing. This tag can sometimes be beneficial in boosting your rankings if search engines display results based on the most recent submissions.
META Name: Robots
<META name="Robots" content="index,follow" />
Robots (spiders), are automated tools used by search engines (and sometimes others) that crawl your site in an effort to categorize the information for displaying search results. Typically, you will submit the main page of your site to a search engine (or it may find it from a link on another site) and the robot/spider would visit your site and crawl all subpages and related links from your main page. By using the robots tag, you can control which pages you would like crawled, and exclude others. For example, you may want to exclude an entire directory, like a CGI directory. Using the robots tag, you can define which pages to follow, which to index and which to ignore completely. This work done by this tag can be done via the robots.txt file as well.
It is useful to note, that some search engines, notably Google, will allow you to use the robots tag to prevent the search results from showing a “Cached” link for your site. Just use the word NOARCHIVE in the content field.
It is also useful to note that the robots tag can be used to prevent the use of the ODP description in search results. Do this by using the word NOODP in the content field.
Finally, note that you can combine multiple content words by separating them with a comma.
<TITLE>Your title goes here</TITLE>
The TITLE tag isn’t really a meta tag, but it is related to them and is worth discussing. Whatever text you place in the title tag will appear at the top of a browser when viewing the web page. This tag is also used by search engines in presenting their search results and is an important ingredient in their formula for creating rankings. Note that some browsers append their own name (e.g., Microsoft Internet Explorer or Mozilla Firefox) to the title you specify.
There are several things to keep in mind regarding the use of these header tags. First, they sometimes get too much attention, especially by those with only a basic knowledge of webmaster and/or SEO tactics. They shouldn’t be neglected, but they are no magic bullet. Second, not all search engines treat the tags in the same way and some search engines ignore tags that other search engines use. This is most notable in the use of the description tag in the search results displayed. Third, while you will often see other people’s sites using commas in META tags, this is actually unnecessary. Finally, make sure you customize all tags in your header to each page.