UST Security trailer BETA
To establish a link between security header and security trailer segment groups.
Security reference number
Unique reference number assigned by the security originator to a pair of security header and security trailer groups.
The value shall be arbitrarily assigned, but the same value shall not be used more than once within the same EDIFACT structure, I.e. interchange, group, message or package.
Number of security segments
The number of security segments in a security header/trailer group pair, plus the USD and USU segments where the security header/trailer group pair is used for encryption.
Each security header/trailer group pair shall contain its own count of the number of security segments within that group pair.
The count of the number of security segments includes the USR segment in the security trailer.