A federal registration which delineates certain limitations on the use of a mark due to the concurrent use of a similar mark. Generally speaking, the first of two companies to use a mark is entitled to nationwide registration rights, except for the specific geographic area in which the second company is using the mark, even if the first user has not used the mark nationwide. If the second user is the first to register, then the second user is the one that receives nationwide registration subject to the first user's geographic region. Concurrent users may agree to leave open certain regions permanently or else long enough for one or the other to begin actual use in that region.