Section 76(6) in The Central Motor Vehicles Rules, 1989
(6)[ A motor vehicle belonging to a diplomatic mission in Delhi or to any of its diplomatic officer shall be assigned a registration mark consisting of the letters CD preceded by the number allotted to the mission by the Ministry of External Affairs of the Government of India and followed by a number allotted to the vehicle by the registering authority in the following manner, namely :(i)an official vehicle meant for the use of the head of a mission shall be allotted the number 1;(ii)personal vehicles of the head of the mission shall be allotted the number 1, followed consecutively, in alphabetical order, by a letter beginning with the letter A;(iii)official vehicles, other than those referred to in clause (i), shall be allotted consecutive numbers beginning with the number 2;(iv)vehicles belonging to other officers of the mission shall be allotted numbers in consecutive order after the last number allotted under clause (iii);(v)vehicles acquired by a mission or by its diplomatic officer other than heads of missions, shall be allotted numbers inconsecutive order after the last number allotted under clause (iv)irrespective of whether such vehicle is for official or personal use of the mission or any of its officers;(vi)a number allotted to a vehicle under any of the clauses (i) to (iv), which is lying unutilised due to sale or export of such vehicle or cancellation of its number may be allotted to another vehicle under the same clause in respect of which an application has been made under sub-rule (1).]
