The Inventory Query/Retrieve (Q/R) Information Model is based on an Entity-Relationship Model Definition and a Key Attributes Definition analogous to those defined in the Basic Worklist Management Service Class Section K.2 Worklist Information Model Definition.
The Inventory Q/R Information Model is a single level entity:
While the Inventory Composite SOP Instances that are the subject of this Service Class contain Attributes associated with the several IEs (see Section 7.13.6 “Inventory” in PS3.3), the Inventory Q/R Information Model operates only on the Attributes of the Inventory IE of the Inventory IOD.