Also known as a unit crest or DUI, the Distinctive Unit Insignia is worn by all Soldiers (except General Officers) in units that have been authorized to be issued the device. It is worn centered on the shoulder loops of the Army Green Service Uniform (AGSU) and the blue Army Service Uniform (ASU, Enlisted only) with the base of the insignia toward the outside shoulder seam. DUIs are not worn on the Dress variations of either uniform, however.
Full guidance on wear of the DUI is found in DA Pamphlet 670-1,
Section 21-22, "Distinctive unit insignia."
♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦
Approved on 6 March 1943, the 6th Maintenance Battalion’s Distinctive Unit Insignia features the Battalion’s motto “For All,” a clever adage in that it embodies the team spirit of the unit while also serving as a pun on the Battalion’s numerical designation (“Four All”).
Rendered all in crimson and yellow (gold), the insignia recalls the Battalion’s origins as an Ordnance battalion. It also tells us that the Battalion was almost surely constituted and activated sometime after 1921 (when those colors were selected as Ordnance colors) and no later than 1944 (the unit is credited with participation in the Leyte campaign). Four flames represent the four functions of Ordnance—Munitions, maintenance, Explosive Ordnance Disposal (EOD), and explosive safety—and are another reference to the Battalion’s numerical designation.
There is no lineage available for the 4th Ordnance or 4th Maintenance Battalions at the U.S. Army Center of Military History. According to Barry Jason Stein’s U.S. Army Heraldic Crests: A Complete Illustrated History of Authorized Distinctive Unit Insignia, the 4th Maintenance Battalion earned credit for participation in the aforementioned Leyte offensive during World War II and was involved in all the campaigns that comprise the Korean War.
One of the Battalion’s companies (Company C) was the subject of a study of the “Summary Accounting for Low Dollar Turnover Items (SALTI)” system published in 1969, and reference is made to the Battalion being part of the U.S. Army Europe Augmentation Readiness Group in Germany in the 1960s/1970s.