if he/she is employed as a teacher in a school under the reasonable direction of the principal of that school;
if he/she is employed by a board on terms under which he is not assigned to any one school, under the reasonable direction of that board and of the principal of any school in which he/she may for the time being be required to work as a teacher.
Exercise of particular duties
A teacher employed as a teacher (other than a principal) in a school shall perform, in accordance with any directions which may be reasonably given to him/her by the principal from time to time, such particular duties as may reasonably be assigned to him/her.
A teacher to whom paragraph 1(b) refers shall perform, in accordance with any direction which may reasonably be ...