Article item number must be globally unique, so remove the superfluous constraint to make it unique only within a single party.
Article item number must be globally unique, so remove the superfluous constraint to make it unique only within a single party.

homeworkprod/byceps,m-ober/byceps,m-ober/byceps,homeworkprod/byceps,homeworkprod/byceps,m-ober/byceps