Issue: URN or URL for namespace URI in schema and WSDL?

Both WSDL and XML Schema for the registry need URIs for several reason,
namespaces being the primary one. A URI may be either a URN or a URL.

One authoring style that I have seen uses a URL syntax to define the
namespace URI, presumably so it can give an overloaded hint as to the
location of the file where the namespace is defined as the
targetNameSpce. This style is used in most of the W3C specs such as WSDL
and XMl Schema.

Others do not like this confusing and overloaded use of a URL and prefer
a URN.

Current RAWS working files use the URL syntax for name space URI. Does
anyone have any advice?

--
Regards,
Farrukh