This document summarizes UK trademark law regarding infringement, invalidity, revocation, and defenses. It outlines the exclusive rights of a trademark owner (S9) and defines infringement as unauthorized use of an identical mark on identical goods/services (S10(1)), use of similar marks on identical/similar goods where confusion may occur (S10(2)), or use of identical/similar marks with reputation on non-similar goods without due cause/detriment (S10(3)). Defenses include comparative advertising identifying the proprietor (S10(6)), use of one's own name/address (S11(2)(a)), and descriptive/intended use (S11(2)(b)-(c)).