Suite shutoff
A suite shutoff is useful only if you can find it safely.
Many suites have stops at fixtures and a larger suite valve in a closet. Occupants who have never looked will not find it during a spray. Look once while the suite is dry.
Learn the valve on a calm day.
Open the mechanical closet, under-sink cabinets, and any labelled access panel. If you cannot find a suite valve, ask the manager where it is and whether you are allowed to use it.
Force nothing.
A seized valve can break and make the leak worse. If it will not turn with reasonable hand effort, stop and call.
Tell someone what you turned.
A closed valve that nobody knows about becomes a no-water complaint two hours later. Leave a note on the door and text the manager.
Questions people ask
Is the suite valve the same as the building main?
No. The building main is a common-element valve and is not an occupant experiment.
What if I have no shutoff in the suite?
Some buildings only isolate at a riser closet. That is a building-contact job.