An unrestricted line officer (shortened to URL officer) is a designator given to a commissioned officer of the line in the United States Navy, who is eligible for command at sea of the navy's warfighting combatant units such as warships, submarines, aviation squadrons and SEAL teams. They are also eligible to command the higher echelons of those units, such as destroyer and submarine squadrons, air wings and air groups, and special warfare groups. At the flag officer level, URL officers may also command carrier strike groups, expeditionary strike groups, patrol and reconnaissance 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. Specialities URL officers include officers from the Surface Warfare, Submarine Warfare, Naval Aviation, and Special Warfare communities, i.e., the Navy's combat communities. In this sense, all URL officers are considered warfare specialists and are designated as either Surface Warfare Officers, Submarine Warfare Officers, Naval Aviators, Naval Flight Officers, SEAL/Special Warfare Officers, or Special Operations Officers (primarily Diver or Explosive Ordnance Disposal (EOD) Officer/Diver). A URL community previously known as General Unrestricted Line has been phased out and no longer accepting new entrants. Officers in this category were not warfare qualified, nor on track to be warfare qualified, and were typically assigned to administrative and support tasks ashore. General URL officers have been replaced by the expansion of the Restricted Line Officer (RL) community into their former skillsets, with most incumbents laterally transferring into the Restricted Line. Comparison to other types of officers Restricted line Differentiated from URL officers are those naval officers whose functions are considered combat support in nature and are designated as either restricted line (RL) officers or staff corps officers. Examples of RL officers include Engineering Duty Officer, Aeronautical Engineering Duty Officer, Aircraft Maintenance Officer, Intelligence Officer, Cryptologic Warfare (formerly Information Warfare) Officer, Meteorology/Oceanography Officer, Public Affairs Officer, Human Resources Officer, and Foreign Area Officer among others. Examples of Staff Corps officers include Supply Corps, Medical Corps, Dental Corps, Medical Service Corps, Nurse Corps, Civil Engineer Corps, Judge Advocate General's Corps and Chaplain Corps. Some RL officers begin their careers as URL officers and transition to RL, the most common examples being Surface Warfare Officers and Submarine Warfare Officers who become Engineering Duty Officers and Naval Aviators and Naval Flight Officers who become Aeronautical Engineering Duty Officers. Still, other