Message

SpecificationIdentification value MUST be 'urn:fdc:peppol.eu:prac:trns:t011:1.1'.

Context
query:QueryRequest/rim:Slot[@name='SpecificationIdentification']
Test
rim:SlotValue[@xsi:type='rim:StringValueType']/rim:Value/text()[matches(normalize-space(), 'urn:fdc:peppol.eu:prac:trns:t011:1.1')]
Usage
/ query:QueryRequest / rim:Slot@name=SpecificationIdentification / rim:SlotValue / rim:Value