The Inventory IOD, like all DICOM IODs, may be extended by the addition of optional Attributes that do not impact the semantics of the basic IOD. This is denoted Standard Extended Conformance (see Section 3.11 “DICOM Conformance” in PS3.2).

While the IOD identifies many optional Attributes that might be managed in a repository database, the creator of an Inventory is allowed to use such Standard Extended Conformance to include any additional data elements that it manages. This may support additional use cases for the Inventory SOP Instances, or may provide direct database record keys in Private Data Elements for implementation-specific processing.