Default to restricted, not to open
Most scopes list the areas to be cleaned and say nothing about anything else, which implicitly treats every other space as fair game if the door opens. On a campus that assumption is wrong often enough to matter. Reversing the default costs one sentence: any room not named in this schedule is not to be entered. It is simple, it survives staff turnover, and it fails in the safe direction.
The rule also handles the situation nobody anticipates. A door normally locked is found open, a new room is fitted out, an area changes use. Under an open default, a cleaner has to make a judgement in the moment. Under a restricted default, they leave it and report it, which is the correct outcome and takes the decision away from the person least equipped to make it.
