Format/length:	an14
HES item:
National Codes:
Default Codes:

Notes:

Definition:
This is a mandatory data element and is a sequentially incremented number for each message within an interchange.

Usage:
For each message within an interchange the CDS MESSAGE REFERENCE is assigned to provide a unique identity (within an interchange).
Although EDIFACT configures a 14 alpha-numeric format, a maximum value of 9999999 is permitted in the format of n7.
Wrap around from 9999999 to 1 must be supported.

CDS-XML Interchanges:
All CDS-XML messages submitted must contain a CDS MESSAGE REFERENCE in both the CDS Message Header.

NHSCDS EDIFACT Interchanges:
All NHSCDS EDIFACT message submitted must contain a CDS MESSAGE REFERENCE in the EDIFACT UNH 0062 EDIFACT Message Reference Number data element. The same data element is also carried in the associated UNT Message Trailer Segment.
EDI gateway management and translation solution sets usually generate the required EDIFACT Service Segments (UNB, UNH, UNT, UNZ).

CDS INTERFACE GATEWAY SERVICE Interchanges:
Not Applicable.
The CDS MESSAGE REFERENCE is generated and inserted into the NHSCDS EDIFACT message or the CDS-XML message as required.