Army Regulation AR 25-50 Preparing and Managing Correspondence establishes three forms of correspondence authorized for use within the Army: a letter, a memorandum, and a message.This regulation applies to the Active Army, the Army National Guard/Army National Guard of the United States, and the U.S. Army Reserve, unless otherwise stated.The proponent of this regulation is the Administrative Assistant to the Secretary of the Army. The proponent has the authority to approve exceptions or waivers to this regulation that are consistent with controlling law and regulations. The proponent may delegate this approval authority, in writing, to members of the Senior Executive Service within the proponent agency. Activities may request an exception or waiver to this regulation by providing justification that includes a full analysis of the expected benefits and a formal review by the activity's senior legal officer. All requests for exceptions or waivers will be endorsed by the commander or senior leader of the requesting activity and forwarded through their higher headquarters to the proponent. Refer to AR 25–30 for specific guidance.Chapter 1 – Preparing Correspondence Chapter 2 – Preparing MemorandumsChapter 3 – Preparing LettersChapter 4 – Listing Enclosures, Placing Tabs, and Assembling Correspondence Chapter 5 – Processing Correspondence and Official MailChapter 6 – Preparing Authority Lines, Signatures, and Signature BlocksChapter 7 – Using Prescribed Forms and LabelsChapter 8 – Marking Classified Correspondence Appendix A – ReferencesAppendix B – Titles and Protocol SequenceAppendix C – Forms of Address, Salutation, and Complimentary CloseAppendix D – Model Authority Lines and Signature BlocksAppendix E – Preparing Mass MailingsAppendix F – Internal Control EvaluationGlossary