An enclosure notation is a line added to a business letter that lets the reader know that there is additional information included. The enclosure notation is placed after the signature on letters typed personally by the sender and after the initials identifying the typist on letters typed by an assistant.
If a letter includes one enclosure, "Enclosure" is typed for the enclosure notation. If more than one enclosure is added, the plural is used followed by a colon and the number of enclosures. Sometimes the number of enclosures is placed in parenthesis. For example, both "Enclosures: 2" and "Enclosures: (2) are acceptable. Typical enclosures include business brochures, pamphlets, calendars and schedules.