If XBiG is being used by an application that conforms to the Namespaces in XML Recommendation, then the following namespace should be used:
http://xbig.sourceforge.net/XBiG
Typical usage would be:
<meta xmlns="http://xbig.sourceforge.net/XBiG"> . . .
It is not a requirement of the XML Namespaces Recommendation that there is any accessible resource at the URI used for a namespace name, although for information purposes, a copy of this file may be downloaded from the above URL.