Enlisted personnel make up the majority of Starfleet's organization. While each commissioned officer must have a general overall knowledge of the various duties and functions within his Division, enlisted personnel are specialists, each one carefully trained to function flawlessly within his own chosen task. Enlisted men are divided into three rank categories: Petty Officers, Chief Petty Officers, and Crewmen.
Petty Officer: Only officers may give orders. If one crewman gives an order to another, he is in the wrong. Furthermore, the second crewman would be in the wrong were he to obey that order. This is because the ordinary enlisted man does not have the authority to give orders, he is not in the line of command. All he can do is pass along to another an order given by an officer, naming that officer. However, the ratio of officers to enlisted men is about 1:8, far too few to supervise every activity. For this reason, the rank of Petty Officer exists. Petty Officers have earned a special status among the enlisted men. They are in effect non-commissioned officers, falling between Ensign and Crewman. Besides being masters in their technical skills, they have been taught command and leadership skills which enable them to smoothly and efficiently supervise a Division in the absence of their commissioned Division Head.
Chief Petty Officer: Each Department aboard ship may have several Petty Officers (usually one per shift per Division). One Petty Officer in each Department will be the Chief Petty Officer. He is senior to all Petty Officers and crewmen within that Department, and is responsible for them to the Department Head.
Ratings and Rates: Used to identify the skills and qualifications of Crewmen. The Rating (specialty) identifies a Crewman as being qualified in a particular field, each of which is contained within its own Division (e.g.: Electronics Crewman, Geology Crewman). The Rate identifies the level of skill he has achieved within that specialty (e.g.: 3rd Class, 2nd Class, 1st Class). Thus a Crewman might be referred to as Geologist 2nd Jones. Training, especially on-the-job training, never ends for a Crewman. His Petty Officer is always drilling him and his mates to develop and hone their skills, whether it be an already existing task or new technology. A Crewman's Rating and Rate can be read from the divisional armband upon the arm of the uniform.
Performance Evaluation: A Crewman's officers and Petty Officer observe the manner in which he carries out his tasks and learns new skills. Such performance marks are appended to his file semi-annually. These marks help determine such factors as Rate advancement, possible promotion to Petty Officer, or even assignment to Starfleet Academy. Responsibility: Each Crewman is assigned to a duty station within a Division, under the supervision of a Petty Officer, who will direct the duties of all Crewmen within that Division during that shift.
Term and Discharge: Unlike officers, enlisted men are not career men. An enlisted man signs on for a Service Term of five years. At the end of that term, he may (at Starfleet's discretion) re-enlist, or he may resign. Every officer or enlisted man leaving Starfleet is given a discharge. Each discharge has a particular Type and Reason, and these will depend up on the circumstances surrounding the discharge and the record of service. Types and Reasons are shown below:
Types: General, Administrative, Honorable, Dishonorable, Medical.
Reasons: Expired Term, Disability, Unsuitability, Fleet Discretion, Dependency, Reserve Status, Retirement.