How to remind others that the room is forbidden to enter?

If you want to remind others that entry into the room is prohibited, the following methods may be helpful to you:

1. You can change to a room with "no entry allowed" before entering other people's rooms. There is a reminder sign. You don’t need to remind others, so others will not enter this room.

2. You can also directly explain to the other party the reason why entry is prohibited. This is a very good solution.