This was just posted today at 9:19 a.m. on a cruise that left on Saturday. Same cruise as the one that said they were not allowing door signs.
Quote: I'm on board as well and just want all of you to know that my door is COVERED from top to bottom with pictures and 3-d mickey and a cruise ship that my daughter drew. It has not been removed. Plus we have seen other doors with signs on them.
We got to the port at 10:30 and received the #3. Our friends showed up an hour later and they had #9. So the number system is first come first serve. End Quote:
So guess we can do the door signs,

and the number system seems to be only for the 1st hour.