## BASE

The `BASE` element gives the base URL for dereferencing relative URLs, using the rules given by the URL specification, e.g.

        <BASE href="http://www.acme.com/intro.html">
    	 ...
    	<IMG SRC="icons/logo.gif">

The image is deferenced to

        http://www.acme.com/icons/logo.gif

In the absence of a `BASE` element the document URL should be used. Note that this is not necessarily the same as the URL used to request the document, as the base URL may be overridden by an HTTP header accompanying the document.