A job in the Army is called a Military Occupational Specialty or MOS and has a number and letter code.

18A ODA Commander Officer- The 18A Branch code is reserved for Special Forces officers who will command ODA's on missions. The 18As also provide the leadership for every other significant leadership position within the Special Forces Community. Each ODA has one 18A assigned to it.
180A Assitant Detachment Commander/ Warrant Officer- 180A's Back up the ODA's 18A commander. Acting as the assitant commander while the team operates together, and is prepared to take command should the 18A be absent, or incapacitated. Should conditions or the mission require it the ODA can split into two equal teams with the 18A and 180A each commanding one part.
18B Weapons Sergeant- 18B's are the weapons specialist, and they are capable of operating and maintaining a wide variety of U.S., Allied, and otherforeign weaponry. Each ODA is normally assigned two 18B's.
18C Engineering Sergeant- 18C's are the engineering specialist for each ODA. They are trained in a range of disciplines, from demolitions and construction of feild fortifications, to topographical survey techniques. Each ODA is normally assigned two 18C's.
18D Medical Sergeant- 18D's are the medical specialist for the ODA's, operating behind enemy lines for months at a time require organic medical capabilities. 18D's are trained with emphasis in Trauma medicine, they also have a working knowledge such skills as Dentistry, Veterinary care, Public sanitation, Water Quality, and Optometry. Each ODA is normally assigned two 18D's.
18E Communications Sergeant- 18E's are the Communications specialist for the ODA's, providing the ability to communicate back to base from virtually any point on earth. 18E's can operate every kind of communications gear, from encrypted satellite communications systems to old style high frequency (HF) Morse code keys, but they also have serious computer/networking skills. Each ODA is normally assigned two 18E's.
18F Operations/Intelligence Sergeant- 18F's are the operations, and intelligence for ODA's that operate for months behind enemy lines. The 18F is fully qualified to collect and evaluate information for transmission back to higher headquarters, as well as supply vital data on enemy units, targets, and capabilities. He will also provide a team with interrogation capability should enemy prisoners be captured. Each ODA normally has one 18F assigned
18Z Operations Sergeant- 18Z's are the Senior enlisted man on the team, Usually referred to as the "Team Sergeant" The 18Z is responsible for making sure the entire team operates as a unit, and is properly outfitted, and supplied. He relieves the 18A and 180A of more mundane tasks, which allows them to concentrate of leading and planning missions for the ODA.
11B Infantryman- The Infantryman’s role is to be ready to defend our country in peacetime and to capture, destroy and repel enemy ground forces during combat. The following are some duties expected of Infantrymen: perform hand-to-hand combat, assist in reconnaissance missions, aid in the mobilization of vehicles, troops and weaponry.
11C Indirect Fire Infantryman- The Indirect Fire Infantryman specifically supervises or is a member of a mortar squad, section or platoon. Some of your duties as an Indirect Fire Infantryman may include: employing crew and individual weapons in offensive, defensive and retrograde ground combat; performing hand-to-hand combat drills that involve martial-arts tactics.
91W Health Care Specialist- The Health Care Specialist is primarily responsible for providing emergency medical treatment, limited primary care and health protection and evacuation from a point of injury or illness for Army Soldiers and civilians.