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 URL officers will transition into Staff Corps communities, most often the Medical Corps or the Judge Advocate General's Corps following completion of Navy-funded medical school or law school, while others move into other RL or Staff Corps fields. The remaining officers are directly commissioned as RL or Staff Corps. RL and Staff Corps 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.[1]
Limited duty officers and chief warrant officers
In contrast to the U.S. Navy's limited duty officers (LDO) and chief warrant officers (CWO), who are directly accessed from the senior enlisted grades (E-6 to E-9 and W-2 to W-5 for LDO; E-7 to E-9 for CWO), traditional unrestricted line officers are required to possess at least a bachelor's degree and complete some type of formal pre-commissioning accession program, such as:
Some senior URL officers in current service as naval aviators or naval flight officers were also commissioned via the since disestablished Aviation Officer Candidate School (AOCS), either under traditional AOCS or via its former subset Aviation Reserve Officer Candidate (AVROC) or Naval Aviation Cadet (NAVCAD) programs. AOCS was merged into the current Officer Candidate School in the late 1990s.