This Style Guide sets forth the general rules the Office of the Executive Secretariat (ES) of the U.S. Agency for International Development (USAID) follows in editing documents. All USAID documents, internal and external, will adhere to this Style Guide. The drafter is responsible for learning and following its rules to ensure consistency in all USAID written products and messages. Adherence to the Style Guide will also reduce errors and strengthen USAID’s ability to communicate our vital mission to the world. ES will return materials that do not adhere to the Style Guide to the drafter for revision. When the guidelines set forth in this Style Guide contradict the document-specific guidelines found on the ES website, the document-specific guidelines prevail. This Style Guide is based on the Chicago Manual of Style (CMS), 17th edition, and Merriam-Webster, online edition.