Shoulder Sleeve Insignia. Description: On a shield shaped like the head of a battle-ax, 2 3/8 inches (6.03cm) in width overall divided diagonally (from upper left to lower right) into two parts, red and blue, separated by a diagonal yellow bar, a crusader's unsheathed sword point to top with white blade and yellow hilt, the blade fimbriated red where it crosses the yellow diagonal.

Symbolism: The crusader's sword (the "Sword of Freedom") was suggested by the shoulder sleeve insignia previously authorized for the United States Military Assistance Command, Vietnam, and the United States Army, Vietnam. The one diagonal refers to the numerical designation of the I Field Force. The sword "piercing" the red area alludes to the constant probing of enemy territory and positions and the driving back and crushing of enemy forces. The colors red, white and blue are the national colors of the United States, and the colors yellow and red, are those of Vietnam. The colors blue, red and yellow are also those of the three major combat arms: Infantry, Artillery and Armor. The silhouette of the shield is shaped like a battle-ax to symbolize the smashing power of the I Field Force and the constant combat readiness of its personnel to engage the enemy. The battle-ax shape, in itself, is also an additional I Field Force identification.

Background: The shoulder sleeve insignia was approved on 5 Oct 1966.

Distinctive Unit Insignia. Description: A gold color metal and enamel insignia 1 3/16 inches(3.02cm) in height overall consisting of a green enamel triangular mountain, the summit behind the lower part of a gold and enamel (scarlet and blue) device in the shape and background design of the authorized shoulder sleeve insignia of the I Field Force, Vietnam; overall an unsheathed Crusader sword with point up, the hilt gold and the blade of white enamel between two gold diagonal tapering rays issuing from the lower edges of the blue area and extending over the green area all within a circular gold scroll passing behind the upper part of the "shield" device and the ends terminating at the gold rays with the inscription "FIRST FOR" on the left and "FREEDOM" on the right all in scarlet enamel letters, the ends of the scroll connected by two narrow gold concentric arcs; the inner arc coinciding with the inner diameter of the scroll, the areas between the scroll, "shield" and mountain being pierced.

Symbolism: The operational and numerical designation of the organization are indicated by the red, gold (yellow) and blue device in the shape and background design of the authorized shoulder sleeve insignia of the I Field Force, Vietnam, the unsheathed Crusader sword, which has become associated with Vietnam, also simulating in this instance the numerical "One (of "First"). The green mountain alludes to the terrain and vegetation of the Central Highlands, the major operational combat area of the I Field Force. The ray allude to constant alertness and combat readiness in both attack and defense and, in leading into and cutting through the mountainous jungle terrain, indicate the "seek and destroy" tactics of jungle warfare; the open circular scroll simulating an envelopment or pincers movement. Jungle trails and lines of communication and supply are indicated by the marrow gold lines and arcs. The motto "First For Freedom" reflects the organization's numerical designation and in the alliterative use of the initial letter of each word alludes to "I (First) Field Force."

Background: The Distinctive Unit Insignia was approved on 4 Oct 1968.