Web Design in a Nutshell, 3rd Edition

Other uses of http-equiv

Here are some other uses of the http-equiv attribute:

expires

Indicates the date and time after which the document should be considered expired. Web robots may use this information to delete expired documents from a search engine index. The date and time format (as shown below) follows the date/time standard for HTTP headers because the http-equiv attribute is intended to mimic an HTTP header field.

    <meta http-equiv="expires" content="Wed 12 Jun 2001 10:52:00 EST" />

content-language

This may be used to identify the language in which the document is written. The browser can send a corresponding Accept-Language header, which causes the server to choose the document with the appropriate language.

This example tells the browser that the document’s natural language is French:

    <meta http-equiv="content-language" content="fr" />

The W3C now recommends using the lang and xml:lang attributes in the html element for language specification, but this method may be used for backward compatibility. For more information on internationalization and a listing of two-letter language codes, see Chapter 6.