I think he is referring to a manually operated dead bolt or those latches at the top of the door. The locks that can only be set and unset from inside of the room.
Latches will work, but 99.9% of doors with Onity locks will only have the deadbolt inside the Onity lock, which is vulnerable to the problem I detailed above. Just something to keep in mind.
No no you're missing the point I think. Nearly every hotel room has a big old manual separate bolt set up higher and away from key based locking system. Slides open maybe 2 inches etc. Twice in my life the hotel person has given my room to someone else by mistake (I travel a lot for work). That is, I'll be in there, twice late at night, and someone else puts in a key and it works. After the first time I always set that manual bolt no matter what - just in case. Not that I think there's any real merit to the original point that kicked off this particular thread.
