This parameter shall be used by the requestor and the acceptor of the association to include DICOM Application Entity user information. Its meaning shall depend on the application context that accompanies the primitive. The usage of this parameter is specified in Annex D.
Notes: 1. This parameter is used to carry initialization information for the DICOM Application Entities as defined in the application context specified by the value of the accompanying Application Context Name parameter.
2. Annex D specifies some user information sub-items, and references PS3.7 for the specification of additional sub-items. PS3.7, in turn, references PS3.4 for the specification of Service-class-application-information used in some sub-items.