(frequently memo), n. (memorandums, memoranda, memos, pl.)A textual communication used principally in business that lacks the formal salutation and complimentary ending of a letter.A short note made as a personal reminder.An informal document detailing the terms of a contract or transaction; a memorial3.
Levy, D., 2001, p. 70–71 The memo1, too, was a product of the search for speed, efficiency, and standardization. It arose most directly from the letter. Letters as a form of personal correspondence had of course existed for many centuries. They were already used in commerce, mainly for external communication. The conventions of letter writing were well established. These included the date of writing, a formal salutation ('Dear . . . ') as well as a formal closing ('Your most . . .') . . . As the letter was increasingly used for internal communication, within and across departments, the new business experts, masters of efficiency, argued for a much simplified format. Typing time could be saved if the company printed up letterheads with fields such as To, From, and Subject, and if openings and closings were stripped down to a bare minimum. . . . ¶ . . . The 'Subject' field had a double purpose. It of course gave the recipient a quick way to determine what the memo was about. But it was equally important as a resource for a new class of workers, the file clerk. It helped the clerk determine where in the vertical files to store the memo.