Property is indexed. Possible indexes are from 1 to 50.

This property can be used to filter in project data navigators. By default, the property is preset with the value of the part property "ERP number" (ID 22056) of the associated part. ERP numbers may be up to 255 characters in length. A max. of 50 definitions can be defined using the index.

Reference

ProjectPropertyList Class
ProjectPropertyList Members