When size, weight, or other factors prevent sending an enclosure with a letter, send it separately and type "(sep cover)" after the enclosure's description. In this article, we explain what an official letter is and how to write one, plus we provide a template and example of an official letter for you to reference.Most appeal and request letters require a page or two. In this article, we explain what an enclosure is and how to cite one, and we provide an example of an enclosure in a business letter. In this post, we'll explore best practices for writing effective closing letters that support clients and foster lasting professional relationships. Add an enclosure notation after your signature at the end of the letter, and abbreviate it with "Enc." or "Encl. Enclosures (if any): If you're enclosing additional documents, like brochures or business cards, mention them at the end of the letter. San Diego, CA 90006. AGENCY CLEARANCE LETTER: Water, Sewer and School fees must be paid prior to permit issuance. Include copies of letters, IEP's, medical records, a log of incidents in the school or community, etc.