6.—(1) Where a person holds, or has held, a relevant full licence authorising him to drive vehicles included in any category or, as the case may be, sub-category he is deemed competent to drive—
(a)vehicles of all classes included in that category or sub-category unless by that licence he is or was authorised to drive—
(i)only motor vehicles of a specified class within that category or sub-category, in which case he shall be deemed competent to drive only vehicles of that class, or
(ii)only motor vehicles adapted on account of a disability, in which case he shall be deemed competent to drive only such classes of vehicle included in that category or sub-category as are so adapted (and for the purposes of this paragraph, a motor bicycle with a side-car may be treated in an appropriate case as a motor vehicle adapted on account of a disability),
and
(b)all classes of vehicle included in any other category or sub-category which is specified in column (3) of Schedule 2 as an additional category or sub-category in relation to that category or sub-category unless by that licence he is or was authorised to drive—
(i)only motor vehicles having automatic transmission, in which case he shall, subject to paragraph (2), be deemed competent to drive only such classes of motor vehicle included in the additional category or sub-category as have automatic transmission, or
(ii)only motor vehicles adapted on account of a disability, in which case he shall be deemed competent to drive only such classes of vehicle included in the additional category or sub-category as are so adapted.
(2) Where the additional category is F, K or P, paragraph (1)(b)(i) shall not apply.
(3) In this regulation and regulations 7 and 8, “relevant full licence" means a full licence granted under Part III of the Traffic Act, a full Northern Ireland licence or a Community licence.