explaining if anyone is confused .... <you may NOT be allowed to add>
cruise ships are often built with many more beds then the number of passengers they are authorized to carry. This affords them flexibility when selling cabins. In this case the room may show a third and even a fourth bed BUT if the 'life boat capacity' has been reached they can not fill the bed.
Actually have a funny story along this line ..... we were booked on a 'year one' MAGIC cruise, family of 4. When we got our room assignment I checked the cruise book and our assigned cabin was NOT marked as having the 4th bed (Pullman drop down) hmmmmm

so I called and asked. Friendly
DCL person explained "all the rooms of that level have the 4th bed but that's not in the book because then we don't meet Coast Guard requirements" .......
INTERESTING thought I ..... CERTAINLY she was not aware she was talking to a serving senior officer of the USCG!!!!!

I was pretty sure what she meant but also pretty sure the average person with the same question might NOT understand ......
WAIT THERE'S MORE
On that cruise I met the Master (wearing a CG Officer uniform was a cheap shot .... 9 time out of 10 I got some sort of special invite

) and was invited to the bridge for the departure from Castaway. <daughter got to push button to sound ship's Mickey horn heading out> We were far from only invited guests on the bridge (pre 9-11) and while trying to stay out of the way I struck up a conversation with another guy about my age. "I know what cheap trick I used to get up here, what was yours?"
He: "I'm a VP for DCL here with a group of our telephone folks for orientation . . . ."
Me: "REALLY .... have I got a story for you" ......
He: "I think I'm scheduling another session with my folks" .....
as we say in the sea services a no S*itt@r .... aka TRUE story ....