Add an enclosure notation after your signature at the end of the letter, and abbreviate it with "Enc." or "Encl. 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."Enclosure" is used with letters. If you have two enclosures, label them Enclosure 1 and Enclosure 2. This manual serves as a guide for Montgomery County Public. Schools (MCPS) staff members who prepare correspondence. A business letter is a formal document and you must follow a format. All the components in the format are addressed in my business letter format page. A cover letter enclosure is a document you include with a physical cover letter, such as a resume or letter of recommendation. The document discusses proper business letter style and formatting, advising writers to use a natural tone and avoid stilted language.