4.2. An approval number shall be assigned to each type approved. The first two digits (at present 03, corresponding to the 03 series of amendments which entered into force on 23 June 2005) shall indicate the series of amendments incorporating the most recent major technical amendments made to the Regulation at the time of issue of the approval. The same Contracting Party may not assign the same number either to the same vehicle type equipped with another type of protective device or whose protection device is mounted differently, or to another vehicle type. a0c0