It would be tremendously helpful if it was possible to attach a type to elements inserted via the extension mechanism. 
This would allow cooperating systems to pass information between each other and retain a high degree of machine-
readability without forcing them to treat the description attribute this way (which, since it is xsd:string and not xsd:
token, is something of a problem at the moment. In particular, if a transport layer decides to reorganize the namespace 
prefixes, the association with particular namespaces will be lost.)