46 CFR §12.703

1. (a)Rating endorsements will be issued without professional examination to applicants in capacities other than Able Seafarer, Lifeboat Operator, Lifeboat Operator-Limited, tank vessel endorsement, or QMED, including—
   1. (1)Ordinary Seafarer;
   2. (2)Wiper;
   3. (3)Steward's Department; and
   4. (4)Steward's Department (F.H.).
2. (b)Holders of MMCs or MMDs endorsed as Ordinary Seafarer may serve in any unqualified rating in the deck or steward's department, except as a Food Handler (F.H.).
3. (c)Holders of MMCs or MMDs endorsed as Wiper may serve in any unqualified rating in the engine or steward's department, except as a Food Handler.
4. (d)Only MMCs or MMDs endorsed as Steward's Department (F.H.) will authorize the holder's service in any capacity in the steward's department, including Food Handler.