Qualified Unrestricted Line (URL) Officers Unrestricted Line Officers (URL Officers) are commissioned Officers of the Line in the United States Navy, both Regular Navy and Navy Reserve, who are not restricted in the performance of duty, and are qualified to Command at Sea the Navy's warfighting combatant units such as warships, submarines, aviation squadrons, and SEAL Teams. They are also qualified to command the higher echelons of those units, known as "major commands," such as destroyer and submarine squadrons, aviation wings and groups, and special warfare groups. At the Flag Officer level, they also command carrier strike groups, expeditionary strike groups, task forces, and Fleet and Force commands. URL officers are also eligible to command shore installations, facilities and activities directly supporting the Navy's warfare mission. Non-Warfare Qualified Unrestricted Line (URL) Officers 110X General URL Officer without warfare qualifications (NOTE: Those Fleet Support Officers (FSO) without warfare qualifications were merged into URL officer designator 110X after 2010, after RL SD designator 170X was phased out, per the 2010 NAVPERS 15839I, Manual of Navy Officer Manpower and Personnel Classifications, Vol. 1, Part A). 130X URL Officer previously qualified Naval Aviator or Naval Flight Officer whose operational flight rating has been terminated for aviation medical or flight performance reasons, or by the individual's personal resignation. Training Designators For Unrestricted Line Officers Restricted Line (RL) Officer designators Officers of the line of the Regular Navy and Navy Reserve who are restricted in the performance of duty by having been designated for aviation duty, engineering duty, aerospace engineering duty, or special duty. RL officers are authorized to command ashore within their particular speciality, but are not eligible for combatant command at sea, which remains strictly within the purview of URL officers. Restricted Line Special Duty (RL SD) Officers Training designators For Restricted Line (RL) and Restricted Line Special Duty (RL SD) Officers ([2-5]x0x) Staff Corps Designators Officers, Regular and Reserve, of all staff corps of the Navy. The eight staff corps (and one Flag Officer) designators are: (6xxx) Limited Duty Officers Officers of the line, or staff, as appropriate by their career field, of the Regular Navy and Navy Reserve appointed for the performance of duty in the broad occupational fields indicated by their former warrant designators or enlisted rating groups. Limited Duty Line Officers (by Community) Limited Duty Staff Corps Officers (by Community) Limited Duty Line Officers (Information Warfare Community) NOTE: 68XX designators