HTML Meta Tag Basics
By Stephen Bucaro
Meta tags are special html tags that are placed in the <head> section of
a webpage to provide information about the webpage to a server. The primary
servers that use meta tags are search engines. There are many different kinds of
meta tags, the two most common being the description and keywords meta tags.
<meta name="description" content="description of this wepage's content">
The description meta tag is used to provide a short description of the
wepage's content. Many search engines use the text in description meta
tag's content attribute just below the title of the wepage in their
search results. Most search engines will truncate this text after about 200
characters, so keep your description short. If the description meta
tag is missing, most search engines will use the first 200 characters of text
on the webpage as the description in their results.
<meta name="keywords" content="keywords, related, webpage, contents">
The keywords meta tag is used to provide keywords related to the webpage's
contents. In the early days of the Web, in order to generate more traffic,
unscrupulous webmasters stuffed the keywords meta tag with the most popular
keywords, like "sex" and "money" even though those keywords had nothing to do
with the webpage's content. Today, no self-respecting search engine reads the
keywords meta tag, instead they gather keywords from the content of the webpage.
<meta name="revisit-after" content="30 days">
The revisit-after meta tag is supposed to tell the search engine how
often it should revisit the webpage, however no search engine reads this
tag because it's totally unnecessary. Instead the search engine can more
reliably determine if the webpage has changed since it's last visit by reading
the Last-Modified entity in the HTTP header. Web hosts fill the
Last-Modified entity with the last-update time stamp of the file.
<meta name="robots" content="index, follow">
The robots meta tag is supposed to tell the search engine if it should
index the webpage, and if it should follow any links on the webpage (in order
to index those pages also). The example robots meta tag tells the
search engine to index the webpage and to follow any links on the webpage. The
example shown below tells the search engine to index the webpage, but do
not follow any links on the webpage.
<meta name="robots" content="index, nofollow">
Shown below are other possible configurations of the robots meta tag.
<meta name="robots" content="noindex, follow">
<meta name="robots" content="noindex, nofollow">
Any self-respecting search engine will respect the robots meta tag,
but there's no law that says they must comply, and in todays highly competitive
search market, every search engine wants to be the one that returns more results
than the others. So don't be surprised if you configure a webpage's robots
meta tag to noindex, nofollow and still find it's contents fully displayed
in search results.