2.1.23 [HTML] Section 12.4, Path information: the BASE element


The specification states:

 The base URI is given by meta data discovered during a protocol interaction, such 
 as an HTTP header (see [RFC2616]).

All Document Modes (All Versions)

The use of the HTTP entity-header fields Content-Location and Content-Base is not supported.


The specification states:

 In HTML, links and references to external images, applets, form-processing programs, style sheets, etc. are always specified by a URI. Relative URIs are resolved according to a base URI, which may come from a variety of sources. The BASE element allows authors to specify a document's base URI explicitly.

IE 7 Mode, IE8 Mode, IE9 Mode (all versions)

The BASE element has no effect on image loading (for example, an IMG element or URL in CSS) in IE7 Mode, IE8 Mode, or IE9 Mode (all versions).