Not to be confused with the oak leaf rank insignia of a Major or Lieutenant Colonel An oak leaf cluster is a miniature bronze or silver twig of four oak leaves with three acorns on the stem that is authorized by the United States Armed Forces as a ribbon device for a specific set of decorations and awards of the United States Army, Air Force, and Department of Defense to denote subsequent decorations and awards.The bronze oak leaf cluster represents one additional award, while the silver oak leaf cluster is worn in lieu of five bronze oak leaf clusters.