This guide covers United States trademark law from selecting a mark through enforcing and maintaining it. It opens with what a trademark is and the distinctiveness spectrum that determines whether a name can be protected at all. It then covers acquisition of rights through use, the geographic limits of common law rights, and everything federal registration adds. Registration chapters walk through the two application bases, the identification of goods and services, specimens, examination and office actions, publication, opposition, and the maintenance filings that keep a registration alive. Enforcement chapters treat likelihood of confusion factor by factor, the defenses that actually succeed, trade dress and the functionality bar, dilution for famous marks, counterfeiting, and cybersquatting. Later chapters cover licensing and the quality control that prevents naked licensing, assignments with goodwill, the ways a mark dies through abandonment and genericide, international strategy in first-to-file jurisdictions, and a portfolio management program.