What does the plaque have to do with anything?
It is a traditional kind of thing on some ships...I think some people bring the plaque up to poke the Navy in the eye...to be fair, with each passing day, it looks more and more like an eye-poke is going to be deserved.
One thing it does do though, is help identify that it was indeed the Captain’s cabin, so it is positive identification in a heap of twisted metal.