Hi, Karen ...
Keep in mind it is a "request" and there are no clothing police to incarcerate a man who doesn't wear a tie on informal nights. HOWEVER, it's good manners to follow the dress code. Kuki's dressy under-sweater follows the TONE of informal, even without the tie.
I sometimes think there should be a literacy test for cruisers so to make sure they understand that the dress code is for the ENTIRE evening and doesn't mean run back to the cabin after dinner and put on your ratty shorts and T-shirts.
My husband's personal dress code:
Casual: Polo shirt, navy blazer, khakis, boat shoes, socks optional
Informal: Dress shirt, tie, navy blazer, dress shoes, socks
Formal: Dinner jacket with all the trimmings.
Packing Hint: Send dress shirt(s) to laundry and have them folded. Put appropriate ties and socks in the shirt bag and toss in the suitcase. No, "Where are my socks with the wombats on them, honey?"
Pamda -- CM First-Time Cruisers Editor