(1) A magnetic mark or metal shim on a [[survey cable]]. Usually located every 100 feet for depth-control purposes.

(2) To measure cable. The act of placing magnetic marks at 100 foot intervals over the useful length of the survey cable.

(3) One of a number of marks on a [[log]] used to compute logging speed. See [[minute mark|minute-mark]].

(4) tic-mark. See [[tic mark]].