Here are two distinct examples of ways to cite enclosures in business letters: Example 1. Abbreviate "Enclosure" with "Enc." or "Encl.Add an enclosure notation after your signature at the end of the letter, and abbreviate it with "Enc." or "Encl. Enclosures. An enclosure can prevent a letter from becoming too detailed. Los Angeles, CA. 12345. Recipient's Address. 3 Enclosures: Form Letters Handbook. Plain Letters Pamphlet. The heading provides the reader a return address. Type the address (minus the writer's name) at the top of the letter.