It is established etiquette by the Joint Chiefs of Staff, United States Department of Defense, the U.S. Army, the U.S. Navy, and the U.S. Air Force that the closing “Respectfully yours” be reserved for the President of the United States (according to U.S. Army standards, this also extends to the first lady and the President_elect).
The Best Formatting for a Business Letter. A business letter is a formal document often sent from one company to another or from a company to its clients, employees, and stakeholders, for example. Business letters are used for professional correspondence between individuals, as well. Although email has taken over as the most common form of correspondence, printed out business letters are still used for many important, serious types of correspondence, including reference letters, employment verification, job offers, and more.