alphabetical authorities

Da "top people" whom folks consult for advice/assistance on a variety of ordinary topics dat are randomly scattered about over da "ol' 26" in da English language.

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.)