Scope note for the property involves partner – P32 Back
Associates to the relationship the persons or groups involved in it.
Each relationship generally involves only two instances of one or more classes. Informal relationships like commercial relations or friendship should be restricted to two persistent items per instance. Therefore, the range quantifiers sould be: 2,2.
Relationships involving more than two partners could be used to express multi-lateral agreements, treaties, etc. although it is preferable to treat structured relationships between several entities as membership in a group. This is mandatory if the duration of the relationship is not the same for all partners.