On cruises of 7 nights or more there will be formal nights. The length of the cruise determines the number of formal nights. On all Princess ships formal night attire runs from khaki slacks & polo shirt to tux. You'll see slacks, polo shirts, dress shirts, ties, no ties, jackets, no jackets, suits, tuxes for men. For women you'll see dressy capris, slacks, dressy tops, dresses, evening gowns. All are welcome. It really is your choice. If you enjoy dressing up, go for it. If you prefer more casual attire, go for it. It's preferred that shorts not be worn in the dining rooms for dinner. But I'm not sure that's enforced. On non formal nights smart casual is the norm. I occasionally see dressy shorts on non formal nights. Enjoy your cruise.