The user information parameter, of the A-ASSOCIATE primitive, can be extended to support the negotiation needs of DICOM Application Entities using the UL Service. This will result in the definition of specific user information sub-items. These sub-items shall be assigned unique item-type values registered in PS 3.7.
Notes: 1. The values of the Sub-Items types in the User Information Field are assigned by this standard in the range of 51H through FFH. Sub-Item values are defined by PS 3.7 and PS 3.8.
2. Succeeding editions of the Standard may define additional user information Sub-Items in a manner that does not affect the semantics of previously defined Sub-Items. Association acceptors compliant to an earlier edition of the Standard are required to ignore such unrecognized user information Sub-Items and not reject an Association because of their presence.