Mk II/Mk III paratrooper helmets), US M1 helmet, and French Modèle 1951 helmet – previously worn by Israeli infantry and airborne troops from the late 1940s to the mid-1970s and early 1980s. Some corps or units have small variations in their uniforms – for instance, military police wear a white belt and police hat, Naval personnel have dress whites for parades, paratroopers are issued a four pocket tunic (yarkit/yerkit) worn untucked with a pistol belt cinched tight around the waist over the shirt. The IDF Air Corps has a dress uniform consisting of a pale blue shirt with dark blue trousers. Most IDF soldiers are issued black leather combat boots, certain units issue reddish-brown leather boots for historical reasons — the paratroopers, combat medics, Nahal and Kfir Brigades, as well as some Special Forces units (Sayeret Matkal, Oketz, Duvdevan, Maglan, and the Counter-Terror School). Women were also formerly issued sandals, but this practice has ceased. Insignia IDF soldiers have three types of insignia (other than rank insignia) which identify their corps, specific unit, and position. A pin attached to the beret identifies a soldier's corps. Soldiers serving in staffs above corps level are often identified by the General Corps pin, despite not officially belonging to it, or the pin of a related corps. New recruits undergoing tironut (basic training) do not have a pin. Beret colors are also often indicative of the soldier's corps, although most non-combat corps do not have their own beret, and sometimes wear the color of the corps to which the post they're stationed in belongs. Individual units are identified by a shoulder tag attached to the left shoulder strap. Most units in the IDF have their own tags, although those that do not, generally use tags identical to their command's tag (corps, directorate, or regional command). While one cannot always identify the position/job of a soldier, two optional factors help make this identification: an aiguillette attached to the left shoulder strap and shirt pocket, and a pin indicating the soldier's work type (usually given by a professional course). Other pins may indicate the corps or additional courses taken. Finally, an optional battle pin indicates a war that a soldier has fought in. Service Military service routes The military service is held in three different tracks: Regular service (שירות חובה): mandatory military service which is held according to the Israeli security service law. Permanent service (שירות