A Practice Note discussing one option for foreign trademark holders seeking to register a trademark in the US. This Note covers the legal framework for and scope of § 66(a) extensions of protection to the US from Madrid Protocol countries. It discusses International Registrations through the World Intellectual Property Organization (WIPO), USPTO § 66(a) applications, priority under § 66(a), use considerations, and maintaining and enforcing § 66(a) registrations (grants of protection).