N.Y.C. Admin. Code § 27-451: § 27-451 Classification.

Public garages shall be classified according to their specific uses as follows:

(a) Group 1. Buildings or spaces used for the parking of vehicles having fuel storage tanks in excess of twenty-six gallon capacity; or used for the parking of vehicles of any size, and in which mechanical repair, body work, or painting of vehicles is conducted, or in which gasoline, oil, or similar products are dispensed. Group 1 public garages shall be classified in storage occupancy group B-1.

(b) Group 2. Buildings or spaces used exclusively for the parking of vehicles having fuel storage tanks of twenty-six gallon capacity or less, and in which no repair, body work or painting of vehicles is conducted, and in which no gasoline, oil, or similar products are dispensed. Group 2 public garages shall be classified in storage occupancy group B-2.