A theoretical or average ship of any one category used in transportation planning (e.g., a Liberty ship for dry cargo; a T-2 tanker for bulk petroleum, oils, and lubricants; a personnel transport of 2,400 troop spaces).
NOTIONAL SHIP
Meaning of NOTIONAL SHIP in English
DOD English dictionary of military terms. Английский словарь военных терминов DOD. 2012