META element
<World-Wide Web> An
element, with tag name of "META", expressing
meta-data about a given
HTML document.
HTML standards do not require that documents have META elements; but if META elements occur, they must be inside the document's HEAD element.
The META element can be used to identify properties of a document (e.g., author, expiration date, a list of key words, etc.) and assign values to those properties, typically by specifying a NAME
attribute (to name the property) and a CONTENT attribute (to assign a value for that property).
The HTML 4 specification doesn't standardise particular NAME properties or CONTENT values; but it is conventional to use a "Description" property to convey a short summary of the document, and a "Keywords" property to provide a list of keywords relevant to the document, as in:
<META NAME="Description" CONTENT="Information from around the world on kumquat farming techniques and current kumquat production and consumption data"> <META NAME="Keywords" CONTENT="kumquat, Fortunella">
META elements with HTTP-EQUIV and CONTENT attributes can simulate the effect of
HTTP header lines, as in:
<META HTTP-EQUIV="Expires" CONTENT="Tue, 22 Mar 2000 16:18:35 GMT"> <META HTTP-EQUIV="Refresh" CONTENT="10; URL=http://www.foldoc.org/">
Other properties may be application-specific.
For example, the Robots Exclusion (http://info.webcrawler.com/mak/projects/robots/norobots.html). standard uses the "robots" property for asserting that the given document should not be indexed by robots, nor should links in it be followed:
<META NAME="robots" CONTENT="noindex,follow">
