The 2020 updated and revised edition of the Clinical-Etiology-Anatomy-Pathophysiology (CEAP) classification system was published online by the American Venous Forum on February 27, 2020. These revisions included adding corona phlebectatica as the C4c clinical subclass, introducing the modifier “r” for recurrent varicose veins and recurrent venous ulcers, and replacing numeric descriptions of the venous segments by their common abbreviations. Based on up-to-date clinical practice guidelines and consensus documents combined with the current literature, the purpose of this article is to interpret the 2020 updated edition of the CEAP classification system and reporting standards, and provide a reference for the popularization and application of this classification system.