ADT/ACK - Merge visit - visit number

An A42 event is used to signal a merge of records for a visit that was incorrectly filed under two different visit numbers. The "incorrect source visit number" identified in the MRG segment (MRG-5 - Prior Visit Number) is to be merged with the required "correct target visit number" identified in the PV1 segment (PV1-19 - Visit Number). The "incorrect source visit number" would then logically never be referenced in future transactions. It is noted that some systems may still physically keep this "incorrect identifier" for audit trail purposes or other reasons associated with database index implementation requirements.