A Practice Note examining the safe harbor under Regulation S of the Securities Act of 1933, as amended, for the offer and sale of securities in offshore transactions outside the US. Regulation S is a safe harbor from the registration requirements of the Securities Act. This Practice Note discusses the basic requirements of Regulation S, the issuer safe harbor under Rule 903, the resale safe harbor for subsequent holders of securities under Rule 904, and the definition of a US person under Regulation S.