The shield is of white and blue, the old and the new colors of the Infantry. The Red Acorn was the badge of XIV Army Corps under which the 15th Infantry fought during the Civil war. The acorn is repeated four times to commemorate the four major engagements in which the regiment participated: Murfreesboro, Chickamauga, Chattanooga, and Atlanta. The rock denotes the fact that the regiment was under the Command of General George Henry Thomas for the battle in which he earned his famous sobriquet: "The Rock of Chickamauga". The Chinese dragon, in gold metal, is indicative of the regiment's service in China during the Boxer Rebellion from 1900 to 1938, of which the period after 1912 was continuous. The sunburst, triangle, and devices atop the coat of arms is symbolic of the Katipunan flag of the Philippine Insurrection.