Second Lieutenant

== United States==
In the United States, second lieutenant is typically the entry-level rank for most commissioned officers. 
In the U.S. Army and the U.S. Marine Corps, a second lieutenant typically leads a platoon-size element (16 to 44 soldiers or marines). In the Army, the rank bore no insignia until December 1917, when a gold bar was introduced to contrast with the silver bar of a first lieutenant.
In the U.S. Air Force, a second lieutenant may supervise flights of varying sizes, depending upon the career field, as a flight commander or assistant flight commander or may work in a variety of administrative positions at the squadron, group, or wing level.
As a result of the gold color of the bars, second lieutenants are often colloquially referred to as Butterbars, Nuggets, Commissioned Privates, or 2nd Luey. 
The corresponding United States Coast Guard and United States Navy rank is ensign.
In the Army Medical Corps, this is the entry-level rank for nurses.