The 540th Support Battalion Distinctive Unit Insignia, more familiarly referred to as a unit crest or a DUI, was first approved for the 40th Armored Quartermaster Battalion on 8 February 1956. It would be redesignated four times over the next thirty years: For the 40th Quartermaster Battalion (March 1961), 540th Maintenance Battalion (April 1975), and twice for the 540th Support Battalion, first in July 1968 and again nearly twenty years later on 18 May 1987.
Buff (gold) is the traditional color of the Quartermaster Corps and the Battalion’s origins in that branch are reflected in the use of buff for the background on the scroll, the Korean gateway, and the fimbriation (think outline or trim) of the triple mount in the center. The light blue background which the triple mount is set against is that of the Korean Service Ribbon, and together they commemorate the unit’s service there; the golden Korean gateway is a reference to the Republic of Korea Presidential Unit Citation the organization was awarded. SEMPER UBIQUE SERVIENS, the Battalion motto, is Latin for “Always And Everywhere Serving.”
Distinctive Unit Insignias are 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. More guidance on wear of the DUI is found in DA Pamphlet 670-1, Section 21-22, "Distinctive unit insignia" and 21–3(d) and (e), "Beret" and "Garrison Cap," respectively.
♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦
According to the veterans-oriented Web site and several newspaper articles, the 540th Support Battalion was subsequently redesignated as the 540th Main Support Battalion. It was a unit in the California Army National Guard and was headquartered at Bell, California. The date it was inactivated, redesignated, or disbanded is unknown.