As you know, Mews distinguishes multiple states in which a room can be. Here is a shortlist of the states.
Dirty
This room needs to be cleaned.
Clean
This room now needs to be inspected, after it was cleaned.
Inspected
A reservation can be checked into this room.
In addition to the above 3 most common states, there are 3 more.
Out of Service (TV needs to be fixed, but room can still be sold)
Rooms that are placed out of service are not highlighted in reports & do not block availability.
Out of order (room is undergoing reconstruction & can not be sold)
Rooms that are placed out of order are highlighted in reports & block availability.
House Use
This is used for internal stayovers that are not actual reservations (e.g. one of the team members stays a night).
You can create a House Use in the Timeline.
House Use blocks availability, but does not show up in any of the reports.