Dragon Kill Points. It is the currency earned for participation in guild activities - later spent to “buy” gear from things the collective group kills.
<Afterlife> on Mithaniel Marr was, I think, the first guild to use this terminology. It spread quickly. They were serverwide best guild for a while with a crap ton of server firsts - later battling it out with other neckbeard poopsocking guilds like <Fire of Heavens> for BotB.