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).
Do you need to write a business letter? Not sure about the best layout to use or what to include in your letter? It's important that all the business letters you write are properly formatted and professional in appearance. When you are writing to prospective employers, colleagues, professional and business connections, the layout of your letter is almost as important as what you are writing. If the letter isn't formatted correctly, doesn't have enough space between paragraphs, and uses a non_traditional font style or size, it can reflect poorly on you.