5.—(1) Subject to paragraph (2), a person who enlists on a versatile engagement shall be enlisted for a term which expires 12 years after the date of his enlistment.
(2) A person who enlists on a versatile engagement in a corps which the competent military authority has approved for this purpose may be enlisted for a term which expires either 24 or 30 years after the date of his enlistment.
(3) A person who has enlisted for a term of service in accordance with paragraph (1) may, after he has completed 3 years’ service, be selected for further service in the regular army for an additional term of the following duration—
(a)12 years commencing on the date his service would otherwise end; or
(b)if he will attain the age of 55 years before the expiry of the period referred to in sub-paragraph (a), until the date on which he attains that age.
(4) A person who is selected for further service under paragraph (3) will be notified in writing by the competent military authority and he may, at any time before he has completed 10 years’ service, exercise the option to undertake such further service.
(5) A person who has enlisted for a term of 24 years’ service under paragraph (2) or who has exercised an option to undertake further service under paragraph (4) so as to serve for such a term may, after he has completed 6 years’ service, be selected for further service in the regular army for an additional term of the following duration—
(a)6 years commencing on the date his service would otherwise end; or
(b)if he will attain the age of 55 years before the expiry of the period referred to in sub-paragraph (a), until the date on which he attains that age.
(6) A person who is selected for further service under paragraph (5) will be notified in writing by the competent military authority and he may, at any time before he has completed 22 years’ service, exercise the option to undertake such further service.
(7) A person who has enlisted for a term of 30 years’ service under paragraph (2) or who has exercised an option to undertake further service under paragraph (4) or (6) may be selected for further service in the regular army for an additional term as described in paragraph (8).
Provided that a person may only be selected for further service in the regular army under this paragraph after he has completed the following number of years’ service in the regular army—
(a)in the case of a person who has exercised an option to extend his service under paragraph (4) or (6) to serve until he attains the age of 55, 6 years; or
(b)in the case of a person who has enlisted for a term of 30 years’ service under paragraph (2) or who has exercised an option to extend his service to serve for such a term under paragraph (6), 25 years.
(8) The additional term of service under paragraph (7) will be either of the duration specified in paragraph (5) or of such other duration (whether longer or shorter) as the competent military authority may exceptionally decide and in any case expiring no later than the date on which the person in question will attain the age of 65.
(9) A person who is selected for further service under paragraph (7) will be notified in writing by the competent military authority and he may exercise the option to undertake such further service provided there are at least 2 years unexpired before the date his service is due to end.
(10) A person who wishes to exercise an option to undertake further service under paragraph (4), (6) or (9) shall give notice in writing to the competent military authority specifying the additional term of service he wishes to undertake and, upon receipt of the notice by the competent military authority, he shall be treated as if he had enlisted for a term which expires at the end of the additional term.
(11) A person who has exercised an option to undertake further service under paragraph (9) may be selected for one or more additional term of further service in the regular army as provided in paragraphs (7) and (8) and if he is so selected paragraphs (9) and (10) shall apply to any such subsequent further service as they applied to the first term of further service.