One piece of the 511th PIR's history is that there was an actual unit shield used while the unit was stateside during World War II. While not a DUI per se, the blue, green and grey shield to the right was taken from an original jump certificate for a 511th PIR Paratrooper.

The blue was for the infantry, the inverted triangle represented a parachute and the green a DZ.

The more well-known DUI (see below) is a modification of this early shield that was known to the veterans of the 511th PIR from 1943-1945. You can see it on some of the few remaining regimental documents from that era, at least the stateside ones: Jump Certificates, letters home, official notices, etc.

Once the 511th PIR and the 11th Airborne Division as a whole sailed for the Pacific Theater in 1944, use of this crest kind of died off. It was used sporadically during the Occupation of Japan, but more common at that time was the "8 Ball" patches and artwork (see below).