Referral-Tree-Lightcraft-Hierarchy

1. Smallcraft (F or U) (0 to 99 tons)
2. Bigcraft (W or Other) (100 or larger tons)
3. Escort (E) (100 to 2,499 tons)
   1. Brig (EB) (100 to 2,499 tons)
   2. Close Escort (EC) (100 to 2,499 tons)
   3. Frigate (EF) (100 to 2,499 tons)
   4. Corvette (EG) (100 to 2,499 tons)
   5. Sloop (ES) (100 to 2,499 tons)
4. Destroyer (D) (2,500 or larger tons)