META Tags Background


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Understanding META tags is critical if you are serious about working with search engines. They can be used to identify the creator of your webpage. Some of the more important META tags are keywords, description, robots, and refresh, which can be used to reload the page, or to load another page.

There are two types of META tags: HTTP-EQUIV and META tags with a NAME attribute.

HTTP-EQUIV

META HTTP-EQUIV tags are the equivalent of HTTP headers. The header of a webpage tells the Web browser information which may be useful for displaying the HTML document.

Now, META tags. Just like normal headers, META HTTP-EQUIV tags usually control or direct the actions of Web browsers, and are used to further refine the information which is provided by the actual headers. HTTP-EQUIV tags are designed to affect the Web browser in the same manner as normal headers.

NAME

META tags with a NAME attribute are used for META types which do not correspond to normal HTTP headers. This is still a matter of disagreement among developers, as some search engine agents (worms and robots) interpret tags which contain the keyword attribute whether they are declared as "name" or "http-equiv," adding fuel to the fires of confusion

Using META Tags

Ok, so you have a brief background on META tags, so what do you actually do with these darn things? One fantastic use is if you ever had people tell you that they are seeing an old version of your page when you know you updated it, you may want to stop their browser from caching the Web pages. META tags, can tell the browser not to cache files, and when to request a new version of the page.

Following are some of the META tags, what they are for, and how to put them into your webpages.

Keyword and Description META Tags

These are probably the most common META tags. Chances are if you manually code your Web pages, you are aware of the "keyword" and "description" attributes. These allow the search engines to index your page using the keywords you specifically tell it, along with a description of the site that you yourself get to write.

Here is an example of a keyword META tag.

Don't get carried away and fill your keywords with words that don't appear in your webpage as it can cause the search engines to ignore your page.

Here is an example of a Description META tag.

Notice
how we managed to use all of our keywords in our description. While it is not necessary to use all your keywords in your description, your description should be rich with your most important keywords if are trying to get a favorable ranking in the search engines.

Another trick is to include the same description enclosed in comment tags, just for the spiders that do not look at META tags. To do that, just use the regular comment tags, like this:

<!--// This page is about the meaning of life, the universe, mankind and plants. //--!>

ROBOTS

The Robots META tag can allow you to exclude pages you don't want to be indexed by the spiders in the search engine. It can also tell the search engine when to come back to look at the page again.

Here is an example of a robots META tag.

The default for the robot attribute is "all". This would allow all of the files to be indexed. "None" would tell the spider not to index any files, and not to follow the hyperlinks on the page to other pages. "Index" indicates that this page may be indexed by the spider, while "follow" would mean that the spider is free to follow the links from this page to other pages.

The inverse is also true, this META tag:

would tell the spider not to index this page, but would allow it to follow any links on this page and index the pages it finds. "nofollow" would allow the page itself to be indexed, but the links could not be followed. The Robots tag allows you full control of how your site will be indexed by a spider. It will not help you with Yahoo as Yahoo indexes your main page based upon a human looking at it and deciding themselves what to do with it.

Expires

This tells the browser the date and time when the document "expires." Dates must be in the RFC850 format(GMT format).

<META HTTP-EQUIV="expires" CONTENT="Wed, 26 Feb 1997 08:21:57 GMT">

Pragma

This is another way to control browser caching. To use this tag, the value must be "no-cache". When this is included in a document, it prevents browsers from caching a page locally.

<META HTTP-EQUIV="Pragma" CONTENT="no-cache">

These two tags can be used as together as shown to keep your content current.

Refresh

This tag specifies the time in seconds before the Web browser reloads the document. It can also specify a different URL for the browser to load.

<META HTTP-EQUIV="Refresh" CONTENT="0;URL=http://www.newurl.com">

Don't forget to place quotation marks around the entire CONTENT attribute’s value, or the page will not reload at all.

Set-Cookie

This is one method of setting a "cookie" in the user’s Web browser. If you use an expiration date, the cookie is considered permanent and will be saved to disk (until it expires), otherwise it will be considered valid only for the current session and will be erased upon closing the Web browser.

<META HTTP-EQUIV="Set-Cookie" CONTENT="cookievalue=xxx;expires=Wednesday, 21-Oct-98 16:14:21 GMT; path=/">

Window-target

This one specifies the "named window" of the current page, and can be used to prevent a page from appearing inside another framed page.

Placement of META tags
META tags should always be placed in the head of the HTML document between the actual <HEAD> tags, before the BODY tag. This is very important with framed pages, as a lot of developers tend to forget to include them on individual framed pages. Remember, if you only use META tags on the frameset pages, you'll be missing a large number of potential hits.