A concurrent use registration, in United States trademark law, is a federal trademark registration of the same trademark to two or more unrelated parties, with each party having a registration limited to a distinct geographic area. Such a registration is achieved by filing a concurrent use application (or by converting an existing application to a concurrent use application) and then prevailing in a concurrent use proceeding before the Trademark Trial and Appeal Board ("TTAB"), which is a judicial body within the United States Patent and Trademark Office ("USPTO"). A concurrent use application may be filed with respect to a trademark which is already registered or otherwise in use by another party, but may be allowed to go forward based on the assertion that the existing use can co-exist with the new registration without causing consumer confusion. The authority for this type of registration is set forth in the Lanham Act, which permits concurrent use registration where the concurrent use applicant made a good-faith adoption of the mark prior to the registrant filing an application for registration. Such registrations are most commonly achieved by agreement of the parties involved, although the USPTO must still determine that no confusion will be caused. Statutory basis The authority of the USPTO to issue a concurrent use registration is set forth in the Lanham Act, section 2 (d), enacted in 1947 and coded at , which states in relevant part: Through these provisions, the Act effectively places three requirements on marks for which a later applicant seeks a concurrent use registration: 1) the later applicant must have used the mark in commerce prior to the time that the earlier registrant filed its application for registration, unless the senior registrant consents to the junior user's registration; 2) the later applicant's use in commerce must have been lawful 3) concurrent use of the marks must not result in a likelihood of confusion. The statute essentially codifies the [[Tea Rose-Rectanus doctrine|Tea Rose-Rectanus doctrine]], established by the United States Supreme Court in two cases decided in 1916 and 1918. The Court had established in those cases that a junior user of a mark that is geographically remote from the senior user of the mark may establish priority over a senior user's claim to the mark in the junior user's area. Any party may voluntarily limit the geographic scope of its application while conceding the rights of another party to