SHOULDER SLEEVE INSIGNIA(II Field Force, Vietnam)Description: On a shield arched at top 2 3/8 inches (6.03cm) in width overall a crusader's unsheathed sword, point to top and with white blade and yellow hilt, superimposed on a blue stylized arrow throughout, shaft tapered and points and angled tips of arrowhead touching top and sides of shield, the areas on each side of the tapered shaft yellow and the areas on each side of the arrowhead red all within a 1/8 inch (.32cm) white border.Symbolism: The shape of the shield and the unsheathed crusader's sword (the "Sword of Freedom") were suggested by the shoulder sleeve insignia previously authorized for the United States Military Assistance Command, Vietnam, and the United States Army, Vietnam. The stylized blue arrow and sword are used to represent the purpose and military might of the II Field Force pressing against, sweeping back, and breaking through enemy forces symbolized by the red areas. The dividing of the red and yellow areas of the shield into two parts allude to the numerical designation of the II Field Force, the colors red and yellow also being those of Vietnam. The colors red, white and blue are the national colors of the United States and further allude to the three major combat arms: Infantry, Artillery and Armor.Background: The shoulder sleeve insignia was approved on 5 Oct 1966.Distinctive Unit Insignia(specific to 51st Infantry since 1930)Description: A gold metal and enamel device 1 5/32 inches (2.94cm) in height overall consisting of a shield blazoned: Azure, a bend Or. Attached below the shield a blue motto scroll inscribed "I SERVE" in gold letters.Symbolism: The shield is blue for Infantry, with the bend taken from the coat of arms of Alsace.Background: The distinctive unit insignia was originally approved for the 51st Regiment Infantry on 24 Jan 1930; amended on 11 May 1937; redesignated for the 51st Infantry (Armored) on 23 Sep 1941; redesignated for the 51st Armored Infantry Regiment on 23 Apr 1942; redesignated for the 51st Armored Infantry Battalion on 6 Nov 1943; redesignated for the 51st Constabulary Squadron on 4 Dec 1946; redesignated for the 51st Armored Infantry Battalion on 22 Jun 1954 and redesignated for the 51st Infantry on 28 Jan 1958.