Just as I said in the paragraph previous to what you quotedYes, I do know the policy. It is optional.
"Now DCL does state that their policy is optional, so people are indeed free to show up as they want. Because that is their policy, I cannot fault the people for doing so. However, it does play into the fact that I don't sail DCL anymore. Of course it is not the only reason, but it is one of them. I much prefer cruise lines where people who show up to formal night wearing a graphic T get politely asked to back to their state room and change. "