Aboard Princess ships, the dress (formal, semiformal, or casual) is prescribed for THE WHOLE EVENING. This means that it is supposed to apply to the shows, the casino, the disco, and all of the lounges after 6:00 PM. I'm a little unclear as to whether it's also intended to extend to the Horizon Court (or other 24-hour restaurant on the lido deck), which is sometimes billed as a casual alternative, so I would like to see greater clarity in this area.
I have noticed a general lack of enforcement of dress codes aboard Princess vessels, and I have also heard quite a few passengers say that they made comments about the lack of enforcement on their cruise evaluations. For better or for worse, it does detract considerably from the formality of the event when a few individuals act with such wanton disdain for the rest. If the company gets enough comments from dissatisfied passengers, I would expect some movement toward tactful but firm enforcement of the dress code ("I'm sorry sir, but the dress this evening is semiformal so you need to a tie an a coat to come into the theater."). I also have every intention of inviting the attention of Mr. Ratliffe to this situation at the earliest opportunity. It's not in the company's best interest to tolerate a situation in which the social missteps of a few passengers are alienating the majority.
If you don't want to dress up for formal evenings, please do yourself, Princess, and our other passengers a favor by booking your next cruise on a line that does not hold formal evenings (Windjammer Barefoot Cruises might be a good choice, and I'm sure that there are others) rather than on a cruise line that does hold formal evenings. That way, you won't be in the position of spoiling everybody else's evening while proving your ignorance of social etiquette to the rest of the passengers.
Thanks in advance.