Although EDIFACT messages had previously been developed for Commissioning Minimum Data Sets (CMDS), the NHS-wide Clearing Service (NWCS) implementation required a single EDIFACT message capable of carrying all local variations of all CMDSs.

Before such an EDIFACT message could be produced it was necessary to remodel all CMDSs to conform to a single structure. In addition, it was necessary to include flow control information required by the NWCS processes.

The resultant, extended CMDSs, are referred to as the Commissioning Data Sets (CDS), for further information please refer to the current version of The NHS CDS Manual.

The CDS is the basic structure used for the exchange of commissioning data between Providers and Commissioners (and other users) via the NWCS and includes Elective Admission List data, and has been authorised to replace the respective CMDSs in most instances. However, the Elective Admission List CDS Type has not yet been authorised.

Consequently the Elective Admission List CMDS will be retained to describe the data flow and its content until the replacement by the Elective Admission List CDS Type is authorised.