hi-heres the main rules and regulations i found :
A. Registrants must be either:
A natural person (i) who is a United States citizen, (ii) who is a permanent resident of the United States of America or any of its possessions or territories, or (ii) whose primary place of domicile is in the United States of America or any of its possessions, or;
An entity or organization that is (i) incorporated within one of the fifty (50) U.S. states, the district of Columbia, or any of the United States possessions or territories or (ii) organized or otherwise constituted under the laws of a state of the United States of America, the District of Columbia or any of its possessions (including a federal, state, or local government of the United States, or a political subdivision thereof, and non-commercial organizations based in the United States), or;
A foreign entity or organization that has a bona fide presence in the United States of America or any of its possession or territories that also (i) regularly engages in lawful activities (sales of goods or services or other business, commercial or non-commercial including not-for-profit activities) in the Unites States, or (ii) maintains an office or other property within the United States.
B. The name servers listed for all .US domain names must be based within the United States of America or any of its possessions or territories.
You understand and agree that when You register one of these domains, that You are prohibited from using any profanity in the domain name.
You are not permitted to purchase private or proxy .US registrations. You shall register for any and all .US registrations using Your personal information, which information You represent and warrant is current, accurate and complete.