Artikel 64

Spare rooms shall not be deducted. The existence, however, of two spare rooms for the use, e.g., of pilots or supernumerary officers will not be considered as rendering the ship a passenger-ship, on condition that the said spare rooms are fitted with not more than four berths in all, including sofaberths.
In passenger-ships having no dining-saloon, smoke-room, pantry, galley, bakery, provision-room, drinking-water filtration or distilling plant, bathroom, washing-place, water-closet, privy or urinal intended for the exclusive use of passengers, the deduction for the corresponding master's or crew spaces shall be cancelled. In the case, however, of ships carrying unberthed passengers, such as pilgrims, and not having any accommodation for berting passengers, this rule shall not apply, except in respect of water-closets, privies or urinals.
Within the meaning of the present article, the expression “passenger-ship” shall include any ship carrying paying passengers, or any ship (even if not carrying passengers) having more than two spare rooms, fitted as described above.