77Determinations to be in writing etc.

77 Determinations to be in writing etc.

Any declaration, approval, authorization, determination, direction or notification made or given under, or for the purposes of, this Act shall be made or given by instrument in writing and any declaration, approval, authorization, determination, direction or notification so made or given, or deemed to be made or given under, or for the purposes of, this Act, may be varied or revoked by instrument in writing by the person authorized to make or give the relevant declaration, approval, authorization, determination, direction or notification.