When a song hits #1 simultaneously on all major Korean real-time charts (tracked by Instiz's iChart, which aggregates Melon, Genie, Bugs, FLO, VIBE, and YouTube Music). A certified all-kill adds #1 on the daily charts too. A perfect all-kill (PAK) goes one step further: #1 on the real-time, daily, AND weekly iChart. That weekly requirement is what makes a PAK so rare. When it happens, the fandom loses its collective mind.
"They achieved a PAK within 24 hours of release. The streaming power is genuinely scary."