Is an assertion required for {http location} EBNF grammar?

There is no WSDL assertion stating that an {http location} or whttp:location
must conform to the EBNF grammar defined in Part 2 Section 6.8.1.1.

Consider the following whttp:location values, which do not conform to this
EBNF grammar:

"/to}wn/{localname}"  (unmatched left brace)
"/town/{local:name}"  (template does not specify an NCName)
"/town/{localname"    (closing right brace is missing)

Should these be considered WSDL errors? If so, should there be an assertion
about the EBNF grammar?  Apache Woden parses the whttp:location attribute
and if it does not conform to the EBNF grammar the {http location} property
is flagged as invalid, but there is no WSDL assertion to use for error
reporting.

Alternatively, Woden could just ignore these grammar errors and treat them
as ordinary string content in {http location} but the problem would still
need to be resolved when the request IRI is constructed by the message
builder.

John Kaputin.