BASE - Document Base URI

Summary

Syntax	<BASE>
Attribute Specifications	HREF=URI (base URI reference) TARGET=FrameTarget (frame to render links in)
Contents	Empty
Contained in	HEAD

Details

The BASE element defines the document's base URI for resolving relative URIs contained within the document. A document cannot contain more than one BASE element. When present, the BASE element must appear in the HEAD, prior to any elements that include a partial URI.

BASE's HREF attribute, required in HTML 4.0 Strict, specifies the absolute URI used to resolve relative URIs. See Using Relative URLs for more details on using and resolving relative URIs.

Most Web pages do not require an explicit base URI since the document's URI is a suitable base. An explicit base URI is only required when the same document may be accessed at different URIs or when the document has no URI (e.g., sending an HTML document by e-mail).

The TARGET attribute is used with frames to specify in which frame all links in the document should be rendered by default. The target frame specified by BASE can be overridden by a given link using the link's TARGET attribute.

If no frame with the specified target name exists, the links are rendered in a new window unless overridden by the user. Special frame names begin with an underscore:

• _blank renders the links in a new, unnamed window
• _self renders the links in the current frame
• _parent renders the links in the immediate FRAMESET parent
• _top renders the links in the full, unframed window

In HTML 4.0, the TARGET attribute value is case-insensitive, so that _top and _TOP both have the same meaning. However, most browsers treat the TARGET attribute value as case-sensitive and do not recognize _TOP as having the special meaning of _top.

More Information

• BASE in W3C HTML 4.0 Recommendation
• BASE in W3C HTML 3.2 Recommendation
• BASE in HTML 2.0 Standard
• BASE in WDG HTML 3.2 Reference
• BASE in Learning HTML 3.2 by Examples

Copyright © John Pozadzides and Liam Quinn. All rights reserved.