Biz Casual in Different Countries

Hi Antonio:
For those of us who either have to travel overseas for business or collaborate/entertain foreign colleagues here in the US, what are some of the key differences in business casual in say continental Europe vs. Great Britain vs. East Asia vs. USA? For simplicity i chose major countries like Germany, Italy, UK and HK. I’m sure it depends on the industry you work in, but just to generalize let’s say IT or media where semi-formal suits are not the norm.