(1) A small blip printed on or notched into various storage media used for timing or counting purposes.

(2) To identify a block of text in order to perform some task on it such as deletion, copying and moving.

(3) To identify an item for future reference.

(4) In digital electronics, a 1 bit. Contrast with space.

(5) On magnetic disk, a recorded character used to identify the beginning of a track.

(6) In optical recognition and mark sensing, a pencil line in a preprinted box.

(7) On magnetic tape, a tape mark is a special character that is recorded after the last character of data.