How to dress when your're (not) doing business in Iran

This month's Conde Nast traveler has a useful pull-out booklet on recommended attire in the middle east. Although it has some missing pieces (e.g. Dubai is there, Abu Dhabi is not), I see that Iran is included. You can read online how to dress for meetings in Iran here. It's interesting because here in the US it's illegal to do business with Iran. So, for US readers the guide is more about "what clothes you're supposed to be wearing when you're not doing business in Iran".