Message

Value MUST be part of code list 'Electronic Address Scheme (EAS)'.

Context
/ubl:UnawardedNotification/cac:SenderParty/cbc:EndpointID
Test
not(@schemeID) or (some $code in $clEAS satisfies $code = @schemeID)
Code lists
Electronic Address Scheme (EAS)
Usage
/ ubl:UnawardedNotification / cac:SenderParty / cbc:EndpointID / @schemeID