16.—(1) Subject to sub-paragraph (2), an authorisation shall remain in force for the period of training proposed in the recommendation.
(2) An authorisation shall lapse in any of the following circumstances—
(a)if the registered teacher ceases to be employed at the school specified in the recommendation for an authorisation or, where the recommendation specified more than one school, if he ceases to be employed at any of the schools so specified unless the occurrence of either event is because of a change of status of the school or schools (as the case may be) to another type of school or schools; or
(b)if the registered teacher ceases to be employed by the institution or body named in the recommendation except—
(i)where that arises because of the change of status of a school at which he is employed to another type of school, or
(ii)where the employer named in the recommendation was a local education authority and immediately on ceasing to be employed by that authority he is employed by another local education authority.