xmlns.com is an internet domain created for the purposes of simple Web namespace management. The rationale for registering xmlns.com was to secure a short, memorable domain suitable for naming concepts for use in RDF and XML vocabularies.
I had a similar problem and struggling, googling for 1 day. But it was a simple mistake that instead of:
{http://ws.somecompany.com/services}ValidateUser
It should be
{http://ws.somecompany.com/services/}ValidateUser
xmlns.com is an internet domain created for the purposes of simple Web namespace management. The rationale for registering xmlns.com was to secure a short, memorable domain suitable for naming concepts for use in RDF and XML vocabularies.
DOAC is a RDF metadata vocabulary to describe professional capabilities of a worker like any curriculum or resume that peopleuse to have in their websites but with much better capabilities.
This version of XHTML provides a definition of strictly conforming XHTML 1.0 documents, which are restricted to elements and attributes from the XML and XHTML 1.0 namespaces. See Section 3.1.2 for information on using XHTML with other namespaces, for instance, to include metadata expressed in RDF within XHTML documents.