I used to be one to expound adhering to the ship's "suggest dress codes".... in favor of creating a particular atmosphere onboard.
However, the cruise line chooses to ignore it's own suggested dress guidelines. There are signs outside the dining rooms saying shorts are not allowed, but I've yet to see anyone turned away for wearing them, even on formal nights.
The fact Carnival isn't willing to show the resolve to show a bit of gumption in dealing with their policies, and setting a particular decorum, in my view leaves it absolultey wide open for anyone to dress however they want, with no thought given to their fellow passengers.
In fact, I'd love to see an entire shipload show up to the dining room on formal night in shorts, tank tops and flip flops. Might clearly demonstrate to Carnival how hypocritical their policies are.