Possible limitation to the number of articles that can be ordered. If the Quantity increment is 6 the article must be ordered in a quantity of 6, 12, 18 etc.

Namespace
cbc urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2
Example value
5
Rules
Identifier/Error message Flag
EUGEN-T68-B09601
Document MUST NOT contain elements not part of the data model.
fatal