An essential expression to note if you plan on staying on the internetz for more than 10 minutes. Used under, but by no means limited to 2 main cirumstances:
1. To express a situation in which can be handled by pros, only.
2. To display high regard for something, be it an object or an act of proness etc.
1. Noob: "0h hai, h0wz d0 i fly me a b0at?"
Pro: "umm, pros only tbh."
2. Jihad 1: "z0mgz t0okz out h3li with pistol kthx"
Jihad 2: "pros only"