The document discusses different types of waiver letters, including letters to waive the GMAT exam requirement for an MBA program, waiver letters for immigration purposes, CLEP fee waiver letters, and GRE waiver letters. It provides tips for writing effective waiver letters such as using a business style, being precise, providing evidence, and avoiding complaints or lies. Readers are advised to check their institution's policies before requesting a waiver and to write convincingly while addressing an exact reason for the request. Sample waiver letters are also recommended to review.