Da seven most common types of alphabetical authorities are:
(1) hexpert --- someone who is super-familiar with voodoo and curses; hopefully he uses said vast witchcraft-knowledge to remove or alleviate said evil spells, not to put them on in da first place!
(2) mexpert --- an individual well-versed in all matters "south of da border".
(3) pexpert --- a plumber who is well-versed in da use of freeze-resistant plastic piping
(4) rexpert --- a learned bookworm on da subject of certain animals, either man's best friend or da huge hunched-over carnivores back in da Jurassic period.
(5) sexpert --- someone who can advise couples on achieving more satisfying intimacy.
(6) texpert --- a dude who knows all about da "black-tea"-rich southern-USA area dat is Ranger Walker's usual stompin' grounds.
(7) vexpert --- a human-nature guru with extensive experience on what pushes people's buttons; again --- as in da first example above --- presumably he uses said know-how to help **reduce** already-existing frustration/distress in others, not to purposely exhibit destructive behavior dat would cause people to **become** wound up when they had felt reasonably calm before! (Da infamous "gettin', getters, got"exchange between Madea and Dr. Phil comes to mind.)

This Jazz Cabbage got me zooted. Jazz Cabbage is less harmful than Squares. I’m smoking that Jazz Cabbage boy.