Message

Element 'cbc:CustomizationID' MUST contain value 'urn:fdc:peppol.eu:prac:trns:t016:1.2'.

Context
/ubl:ApplicationResponse/cbc:CustomizationID
Test
normalize-space(text()) = 'urn:fdc:peppol.eu:prac:trns:t016:1.2'
Usage
/ ubl:ApplicationResponse / cbc:CustomizationID