User blog comment:Juracuille/Haoshoku Haki/@comment-110.233.173.16-20100811133618

Ace and Rayleigh are shown to have the Haki to knock numerous people out, but they've never been said whether they have the King's Haki. On the other hand Whitebeard himself was a confirmed KH user (said by a WB crew member) but he's never been shown to knock people out with only Haki. Until Oda decides to tell us the difference between the two kinds, we don't know if knocking people out = KH or not.