Perfect all-kill

A perfect all-kill (Korean: 퍼펙트 올킬; abbreviated as PAK) occurs when a song simultaneously places at number one on the real-time, daily, and weekly components of iChart, which tracks South Korean music streaming services. iChart is run by Instiz Corporation, the South Korean web entertainment publisher that also operates the Instiz web forum. The term "perfect all-kill" was first used when the song "Nagging" by IU featuring Seulong ranked at number one on all Korean music charts in June 2010. Although Instiz iChart was launched in March 2010, it does not list 2010 records.