This definition appears very rarely
See other meanings of PNOK
Samples in periodicals archive:
The announcements are made on the Web site no earlier than 24 hours after notification of the service member's primary next of kin," it explained.
Another recent reform is the assignment of casualty officers to assist not only the primary next of kin, but to also help other relatives.
8) If the appointing authority grants an extension, he is responsible for the release of status information from the investigation, first to the primary next of kin (PNOK) (9) and then to the public, if necessary.