American trademark law does not run on a single switch marked "registered" or "unregistered." It sorts every brand into one of three tiers of protection: common-law rights that arise the moment a distinctive mark is used in commerce, registration on the Supplemental Register for descriptive marks that are capable of distinguishing but not yet distinctive, and registration on the Principal Register, which carries the Lanham Act's full arsenal of presumptions and priorities. This UpLaw guide explains how a mark's place on the Abercrombie distinctiveness spectrum decides which tier it can occupy, what each tier gives and pointedly withholds, and how secondary meaning under Section 2(f) carries a descriptive mark up the staircase. It maps the geographic reach of each tier, the constructive-notice and constructive-use machinery of Sections 22 and 7(c), the incontestability regime of Sections 15 and 33(b), and the ways rights are lost through abandonment, naked licensing, and genericide. It closes with a strategy framework, three worked hypotheticals, a side-by-side comparison, and a practical FAQ, all anchored in primary and secondary authority.