An overcrowding notice shall state in relation to every room on the premises—
what in th opinion of the local housing authority is the maximum number of persons by whom the room is suitable to be occupied as sleeping accommodation at any one time, or
that the room is in their opinion unsuitable to be occupied as sleeping accommodation;
and the notice may specify special maxima applicable where some or all of the persons occupying the room are under such age as may be specified in the notice.
An overcrowding notice shall contain either—
the requirement set out in section 360 (not to permit excessive number of persons to sleep on premises), or
the requirement set out in section 361 (not to admit new residents if number of persons is excessive;
and where the local housing authority have served on a person an overcrowding notice containing the latter requirement, they may at any time withdraw the notice and serve on him in its place an overcrowding notice containing the former requirement.