237   Manner and form in which directions to be given

(1)  A direction under this Act must be in writing, may be served personally or by post and may be varied or revoked by a further direction in writing so served.

(2)  A direction under section 93, 95, 103, 104 or 107 may instead be given orally in cases of emergency.

(3)  A direction under section 230 may be given orally.