Belts

Some quick research led me to this tip on belts:

When is it inappropriate to step out without a belt?
For starters, if you're tucking your shirt into your pants, then you should wear a belt -- unless it's casual Friday at the office. I recommend you wear a belt at all times, although it's not mandatory on weekends or while wearing jeans, on casual occasions
[Full article here]

So apparently belts are not mandatory with jeans or on the weekends? I never knew the belt rules were so liberal.