The 398th Regiment Distinctive Unit Insignia, better known as a unit crest or a DUI, was originally approved for the 398th Infantry Regiment, Organized Reserves on 7 October 1933. It was redesignated for the 398th Infantry Regiment, Organized Reserve Corps on 21 August 1952 before being given its current designation on 30 October 1961. “On The Alert,” the Regimental motto, was added on 18 December 1961.
A blue shield is employed to commemorate the organization’s origins in the Infantry branch, with a wavy bend dexter symbolizing the Kanawha River, found in the general area of West Virginia where the organization was originally allocated. Below the bend is a Diamond Rattler, a reference to the title given to military organizations in the state of West Virginia.
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.
Full guidance on wear of the DUI is found in DA Pamphlet 670-1,
Section 21-22, "Distinctive unit insignia."♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦
The 398th Regiment was originally constituted on 23 July 1918 in the National Army as the 398th Infantry and assigned to the 100th Division, but was demobilized in a few months because World War I had come to a end. It was reconstituted in the Organized Reserves with the same designation and assigned to its prior parent organization as 24 June 1921 and was subsequently ordered into active military service in November 1942. Serving with the 100th Infantry Division in the European Theater, the Regiment was awarded three campaign streamers and its 3rd Battalion tapped for a Presidential Unit Citation for actions during the heavy fighting around Bitche (March 1945) and Heilbronn (April 1945).
After a short inactivation following the end of WWII, the Regiment was redesignated as the 398th Parachute Infantry, an element of the 100th Airborne Division in October 1946, a role it held until August 1950 when it was reorganized and redesignated as the 398th Airborne Infantry. In less than two years, it would again be reorganized and redesignated as the 398th Infantry, an element of the 100th Infantry Division, on 12 May 1952.
Another seven years would elapse before the Regiment was given its current designation as the 398th Regiment, an element of the 100th Division (Training) and assume the Training mission it still carries out today. Like many Training Regiments, the 398th was reorganized several times in the decades between its initial designation and today, with the most significant coming in August 2015 when it ended its decades-long affiliation with the 100th Infantry Division and its three Battalions (1st, 2nd, 3rd) were made elements of the 95th Training Division. As of January 2012, all three Battalions are assigned to the 3rd Brigade, 95th Training Division, 108th Training Command in the United States Army Reserve.