Okay, anyway, I think I know what you mean. Yes, NW does have a written policy that the FC/WBC lavs are for the exclusive use of pax seated in those cabins. Of course, we make exceptions for elderly/disabled pax. It is also a required announcement in our announcement handbook. We don't, as a matter of course, threaten pax w/arrest for ignoring this unless it becomes a repetitive problem from an individual.

In the case of a lav situated by a cockpit door, it is a security issue and even pax seated in FC/WBC are not supposed to be allowed to stand near the cockpit door to wait for an occupied lav.

In cases where the lav is not situated near the cockpit, it is a matter of

1) pax seated there pay a premium for the convenience of designated FC/WBC lavs.
2) it is disruptive to the service.
3) it is disruptive to the pax seated there.