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. The document provides a sample business letter format with enclosure that can be used as a template for professional correspondence.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. Add an enclosure notation after your signature at the end of the letter, and abbreviate it with "Enc." or "Encl. First, find out the correct formal form of address for the king: His Royal Majesty; His Majesty the King of…, etc. The notations Enclosure(s), Encl. , Attachment(s) and Att. Learn the art of formal letter writing. Discover how to write and propperly format your formal letters. Learn the art of formal letter writing.