Insignia and badges of the United States Marine Corps are military "badges" issued by the United States Department of the Navy to Marines who achieve certain qualifications and accomplishments while serving on both active and reserve duty in the United States Marine Corps. As described in Chapters 4 and 5 of Marine Corps Uniform Regulations, "badges" are categorized as breast insignia (worn immediately above ribbons/medals), identification badges (usually worn at breast pocket level), and marksmanship badges (worn immediately below ribbons). For the purpose of this article, the term "badge" shall be used exclusively to describe identification badges and marksmanship badges, and the term "insignia" shall be used for other worn accoutrements, according to the language in Marine Corps Uniform Regulations. The modern-day United States Marine Corps currently maintains the following breast insignia and identification badges: Breast Insignia As per Marine Corps Assignment, Classification and Travel Systems Manual (ACTS MANUAL) MCO P1000.6, Marines wear the appropriate breast insignia for qualification or designation in aviation, parachutist, explosive ordnance disposal, and diving. Authorized breast insignia are worn on the left breast of all service and dress coats. They may optionally be worn on khaki shirts when the shirt is the outermost garment, utility coats or maternity work uniform coats. Miniature versions exist for evening dress jackets. When worn alone, it is worn in the same position a single ribbon would be worn. When worn with ribbons, medals, or marksmanship badges, it is positioned above such awards. On combat utility uniform coats with slanted pockets, it is worn above a horizontal line tangent to the highest point of the pocket or "U.S. MARINES" service tape. No more than two USMC-approved breast insignia shall be worn at any one time. When two insignia are worn they are ordered from top to bottom in the following order with separation in between: diver, EOD, parachutist, aviation. A Marine with more than one insignia within the parachutist, EOD and diver groups may only wear the senior insignia of the group. Marines may wear two insignia from the aviation group. Aviation Insignia Aviation Insignia are breast insignia that are issued to Marines who are qualified or designated to perform duties related to operation and support of Marine aircraft. Officer insignia include the Naval Aviator insignia and Unmanned Aerial System (UAS) Officer insignia for pilots and the Naval Flight Officer (NFO) insignia for non-piloting officers. There is also an astronaut