Although officials of the Islamic Republic are not allowed to wear a tie, it is very common for visiting foreigners to do so though proper business attire need not include a tie in Iran. Women must adhere to the Islamic dress code referred to below.
It is important to note that most officials will not shake hands with a member of the opposite sex, especially in public. It is highly recommended not to create an awkward situation by extending one’s hand. The same is true for private citizens who are particularly religious.
Iranian officials are extremely sensitive to references to the Persian Gulf, and insist that this internationally-recognized name to be used. It is highly recommended to avoid using “the Gulf” and especially “the Arabian Gulf” when addressing this body of water.
Source: Atieh Bahar