I think if you know the rules

[Myriad]

I think if you know the rules in detail for QBI, you could probably start your own tax practice.
I thought the tax reform was supposed to simply taxes…

Back to the question, this website has really good info on various tax topics.

Qualifying A Rental Real Estate Enterprise As A “Business” For The 20% 199A QBI Pass-Through Deduction

The IRS issued this
https://www.irs.gov/pub/irs-drop/n-19-07.pdf