What are meta tags?
Meta tags are tags that reside in between the <head> and
</head> tags of your html. There are two different types
of meta tags. One uses the NAME attribute, and the other uses the
HTTP-EQUIV.
- NAME: The name tags that do not correspond to HTTP headers.
-
HTTP-EQUIV: These are tags that do correspond to http headers.
Why use meta tags?
The http-equiv tags do not need to be used. In fact, neither do the name tags,
except, without name tags, your website cannot be indexed by many search engines.
Most search engines use a bot to crawl through the pages of your website,
these bots look for certain name tags, that give information such as keywords
and a description of the page. That data is then stored in the search engines
database. An example of a typical meta name meta tag is:-
<meta name="keywords" content="key,word,about,my,site">
<meta name="description" content="my page is about bla">
At minimum you should put these tags in your pages.
The NAME tags
I have listed a load of name tags that can be used, but only the ones
marked with an * actually need to be used.
Description*
This is a short description of what is on the page. Important when the pages is
a frameset.
<meta name="description" content="This site is full of
code for programmers.">
Keywords*
These are important words that have something to do with the page. Words like
the and other insignificant words would be ignored by the spider.
<meta name="keywords" content="c++, code, programming">
Author
This is the name of the author of the page.
<meta name="author" content="chris maunder">
Generator
Usually the name and version number of the tool used to make the page. With most
programs, this is added to pages automatically. Possibly used by the application
vendors, to discover market penetration.
Copyright
This is who the copyright for the page belongs to.
<meta name="copyright" content="chris maunder">
Robots
Controls how a spider indexes that page.
- NOINDEX - tells the spider not to index anything on the page.
- NOFOLLOW - tells the spider not to follow links on the page, and index
those as well.
- NOIMAGEINDEX - tells the spider not to index images on the page.
- NOIMAGECLICK - tells the spider not to link directly to the image, but to
the page it is on instead.
- [Google Only (I think)] NOARCHIVE - tells the spider not to cache
the page.
<meta name="robots" content="NOINDEX">
The HTTP-EQUIV tags
Expires
This is used when the content on the page would expire. If a spider detects
this, it would either delete the page from the search engine database, or
re-index the page on the expiry date.
<META HTTP-EQUIV="expires" CONTENT="Thu, 27 Jun 2002 10:56:57 GMT">
Cache-Control
Tells the browser how to handle its caching of that page.
- PUBLIC - may be cached in publicly shared caches.
- PRIVATE - cached only in a private cache.
- NO-CACHE - do not cache the page.
- NO-STORE - may be cached but not archived.
<META HTTP-EQUIV="cache-control" CONTENT="no-cache">
Content-Type
This causes the browser to load the correct character set before loading the
page.
<META HTTP-EQUIV="Content-Type" CONTENT="text/html;
charset=iso-8859-1">
Content-Style-Type
This is how styles are defined in the page.
<META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css">
Content-Language
This of course, is the language the page is in.
<META HTTP-EQUIV="Content-Language" CONTENT="EN-GB">
Refresh
This tag causes the page to refresh and load the specified page after a
specified amount of time. The delay is in seconds.
<META HTTP-EQUIV="Refresh" CONTENT="10; http://www.codeproject.com">
Set-Cookie
This allows the page to set a cookie to expire on a certain date.
<META HTTP-EQUIV="Set-Cookie" CONTENT="cookievalue=cp;
expires=Thu, 27 Jun 2002 10:56:57 GMT; path=/">
