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
 
SG1
    
M
99
USH-USA-SG2
 
USH
4
M
1
Security header
 
USA
5
C
3
Security algorithm
 
SG2
    
C
2
USC-USA
 
USC
6
M
1
Certificate
 
USA
7
C
3
Security algorithm
 
USB
8
M
1
Secured data identification
 
SG3
    
M
9999
USX-USY
 
USX
9
M
1
Security references
 
USY
10
M
9
Security on references
 
SG4
    
M
99
UST
 
UST
11
M
1
Security trailer
 
UNT
12
M
1
Message trailer
 
UNZ
13
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