The document outlines new postal rates that went into effect on January 21, 2018 for various USPS mail classes including First-Class Mail, Priority Mail, International Mail, and more. The rates increased slightly for most mail classes, generally by 1-3% but some saw larger increases up to 15%. The document provides a side by side comparison of rates before and after the change for different mail formats, weights, and classes to help mailers understand the new pricing structure.