This document summarizes the law around cancellation of instruments in India. It discusses the key sections of the Specific Relief Act (Sections 39, 40, 41) regarding when instruments can be cancelled and who can file suits. It outlines the essential elements to file a suit, including that the instrument must be written, void/voidable, and if left outstanding may cause serious injury. It provides examples of the scope of cancellation for different types of instruments like gift deeds, mortgage deeds, and sale deeds.