Sometimes called Close-Quarters Combat (CQC or close combat), World War II-era American combatives were largely developed by Britain's William E. Fairbairn and Eric A. Sykes. Also known for their eponymous Fairbairn-Sykes Fighting Knife, Fairbairn and Sykes had worked in the British Armed Forces and helped teach the Shanghai Municipal Police (SMP) quick, effective, and simple techniques for fighting with or without weapons in melee situations. Similar training was provided to British Commandos, the First Special Service Force, Office of Strategic Services, Army Rangers, and Marine Raiders. Fairbairn at one point called this system Defendu and published on it, as did their American colleague Rex Applegate. Fairbairn often referred to the technique as "gutter fighting", a term which Applegate used, along with "the Fairbairn system".