Segment
No
Status
Max. Occ.
Segment
   
 
UNA
1
C
1
Service string advice
 
UNB
2
M
1
Interchange header
 
UNH
3
M
1
Message header
 
SG4
    
C
99
USL-SG5
 
USL
4
M
1
Security list status
 
SG5
    
M
9999
USC-USA
 
USC
5
M
1
Certificate
 
USA
6
C
3
Security algorithm
 
UNT
7
M
1
Message trailer
 
UNZ
8
M
1
Interchange trailer
Max. Occ. = Maximum occurrence of the segment/group, Status: M=Mandatory, C=Conditional, R=Required, O=Optional, A=Advised, D=Dependent