When sending a dictated business letter, use reference initials to indicate who typed the letter. Reference initials are only used in this circumstance; if you typed the letter yourself, there is no need to include them. Reference initials consist of the initials of the person sending the letter, followed by the initials of the typist.
Reference Initial Placement
Reference initials are placed on the bottom of the letter page, formatted to the left side. Unless there is an enclosure with your letter, the reference initials will be placed on the bottommost line of the page. If there is an enclosure, place the reference initials above the enclosure line, separated by one blank line.
Reference initials consist of the sender's initials in capital letters, followed by the typist's initials in lowercase. The two sets of initials are separate by a colon -- though a slash may be used as well. Periods are not used in reference initials. For example, if Brian Martin is taking dictation for Mary Lawson, the reference initials will appear as follows: