Components: <ID number (NM)> ^ <check digit (NM)> ^ <code identifying the check digit scheme employed (ID)> ^ < assigning authority (HD)>

Subcomponents of assigning authority: <namespace ID (IS)> & <universal ID (ST)> & <universal ID type (ID)

Length≤100
4 components
1O-ID number (NM)
2O-check digit
3O-code identifying the check digit scheme employed
4O-assigning authority