To identify an erroneous simple, composite or component data element, and to identify the nature of the error.
UCF
Functional group response
To identify a functional group in the subject interchange and to indicate acknowledgement or rejection (action taken) of the UNG and UNE segments, and to identify any error related to these segments. Depending on the action code, it may also indicate the action taken on the messages within that functional group.
UCI
Interchange response
To identify the subject interchange, to indicate interchange receipt, to indicate acknowledgement or rejection (action taken) of the UNA, UNB and UNZ segments, and to identify any error related to these segments. Depending on the action code, it may also indicate the action taken on the functional groups and messages within that interchange.
UCM
Message response
To identify a message in the subject interchange, and to indicate that message's acknowledgement or rejection (action taken), and to identify any error related to the UNH and UNT segments.
UCS
Segment error indication
To identify either a segment containing an error or a missing segment, and to identify any error related to the complete segment.
UNA
Service string advice
To define the characters selected for use as delimiters and indicators in the rest of the interchange that follows.
UNB
Interchange header
To start, identify and specify an interchange.
UNE
Functional group trailer
To end and check the completeness of a functional group.
UNG
Functional group header
To head, identify and specify a functional group.
UNH
Message header
To head, identify and specify a message.
UNS
Section control
To separate header, detail and summary sections of a message.
UNT
Message trailer
To end and check the completeness of a message.
UNZ
Interchange trailer
To end and check the completeness of an interchange.