On this topic:
NOTE: This information is referenced from ASC/X12 and may not be current. For the latest information please visit the ASC/X12 web site.
To report implementation errors in a data segment and identify the location of the data segment.
REF IDENTIFIER NAME REQ TYPE MIN/MAX NOTES 01 721 Segment ID Code M ID 2/3 02 719 Segment Position in Transaction Set M N0 1/10 03 447 Loop Identifier Code O AN 1/4 04 620 Implementation Segment Syntax Error Code O ID 1/3