Incoming HSM requests (as HALs == HSM action lists) are assigned a compound id in the MDS_HSM_REQUEST handler. Then when the CDT builds scans for actions send to the CT it will only put actions with the same compound_id in an outgoing HAL. The use case for the compound_id is not so clear and honoring it in this way inhibits batching of actions into HALs. (RBH uses only one action per HAL when it issues HSM requests.)