that shows detailed spell/skill/ability description when your mouse hover over the action bar?
use to have it, but cant find any after WLK...I'm really struggling with DK abilities, as each time i want to know whats that icon means then i have to check spell book!
Hmm I always though that was a standard thing? Are you sure you're not using a tooltip addon or actionbar addon that have the option to disable this? I know Dominos has the option to disable tooltips on the actionbars.
It's possible that it's this addon that gives me tooltips as well though, but I'm not sure about that.