Standard Installation and Division Personnel Reporting System (SIDPERS) was the main database or, rather, databases for personnel accounting by the United States Army. The Active Army, US Army Reserve, and Army National Guard each had separate, largely incompatible databases, each bearing the name SIDPERS or a variation thereof. RC-SIDPERS was nominally designed for both reserve components (Army Reserve and Army National Guard), but was further adapted for use by the National Guard, to create NG-SIDPERS.