(3)For the purposes of every other provision of the said Act and of these rules each of the following separate bodies shall be "corps":-(a)Every battalion.(b)Every company which does not from part of battalion.(c)Every Regiment of cavalry, armoured corps or artillery.(d)Every squadron or battery which does not form part of a regiment of cavalry, armoured corps or artillery.(e)Every school of instruction, training centre, or regimental centre.(f)Every other separate unit composed wholly or partly of persons subject to the Act.