a written form of communication not signed but initialed in the lower right‐hand corner of the last page of the text by a duly authorized signing officer.

a written form of communication between states and on behalf of government signed by the foreign minister or diplomatic envoy of the sending state.

a written communication to a chief of a mission or to a member of his staff. It may be signed by the chief of a mission without his title, or by a member of his staff over his diplomatic title.

a written form of communication with foreign governments and/or their diplomatic and consular representatives