Article Title: Government Jobs: Cracking the GS Code
Article Excerpt: "...Federal job classification systems vary by agency, but the most widely used is the General Schedule (GS), which covers most civilian white-collar positions. Most federal employees must be U.S. citizens or nationals, though limited exceptions exist under specific legal authorities. Beyond that, qualification standards depend on the occupation and agency.
The U.S. Office of Personnel Management (OPM) offers a General Schedule Overview that highlights how the GS is the most common federal pay/classification system for white-collar employees. ..."
Reference Source: www.military.com