s 133 Detention: limits on powers
(1) The maximum term of detention that a commanding officer may award under row 1 of the Table in section 132 to an able rate, marine, soldier or airman is— (a) 90 days if the commanding officer has extended powers for the purposes of this subsection; (b) otherwise, 28 days. (2) A commanding officer may not award detention under row 1 of the Table in section 132 to a person of any of the following ranks— (a) leading rate, (aa) corporal in the Royal Marines; (b) lance corporal or lance bombardier in any of Her Majesty’s military forces , (c) corporal in any of Her Majesty's air forces, unless the commanding officer has extended powers for the purposes of this subsection; and the maximum term of detention that a commanding officer may (if he has those powers) award such a person is 90 days. (2A) In relation to the Royal Air Force Regiment, the reference in subsection (2)(c) to a corporal is to be read as a reference to a lance corporal. (3) A commanding officer has extended powers for the purposes of subsection (1) or (2) if he has, within the relevant time (defined by section 135A) — (a) applied to higher authority for extended powers for the purposes of that subsection; and (b) been notified by higher authority that his application has been granted. (4) A commanding officer also has extended powers for the purposes of subsection (1) or (2) if he is of or above the rank of rear admiral, major-general or air vice-marshal.