Hi @Pete Woelfel - interesting set of questions. Credit score is not a protected class. Google fair housing laws - the issue arises when you turn away someone in a protected class and rent to someone else, who is not a member of that protected class and they find out and get upset and file a discrimination complaint. So here is what you can do about it, a lot of it according to Mike Butler's book Landlording on Auto Pilot (He was a cop before).
1.) Know fair housing laws and don't discriminate against the following federal protected classes: sex, color, religion, national origin, age, disability, family status incl. pregancy. Additional Wisconsin protected class are lawful source of income, sexual orientation, martital status, ancestry and victims of domestic abuse/crimes.
2.) Never actually reject anyone, in particular in writing. First it sucks to get told you are not good enough and I don't want to do that to anyone. Second, if you do so the next question will be why - and that's the question that can get you in trouble.
Butler's recommendation is to rank people using a score that involves criteria that are not protected classes (neat & clean or not, smoker or not, etc..) and then rank them. It is not as upsetting to someone to make second place (we would have rented to you, but we had an even stronger application) than being flat out rejected. He also uses a stalling tactic - more information needed, incomplete application, etc to deal with people who are persistent.
I usually take the time to leave people with some helpful and encouraging feedback, tell them about creditkarma etc - and they are super thankful, because they got turned down before and nobody ever gave them useful feedback. In over ten years I had one issue with an applicant who was mentally a little on edge and felt she has been discriminated by the color of her skin, the fact that we rented to someone else of the same color was not good enough for her LOL - she complained, but it never went anywhere.
Notice how this works so much better with single family properties than appartment buildings? Once a SF is filled there is no more opportunity. If you manage a 100 unit low income apartment building things become a little bit more difficult.
To your question: credit score is not a protected class. And it's also not visible when looking at a person.
We are a little flexible with credit score. There is nothing matic about 600. The service we use (mysmartmove.com) allows me to see their payment history on every reported item - I am more concerend about their payment moral than overall score. If I see that someone has been paying like clockwork I am more inclined to accept a lower score. A lot of people have what I call a skinny report, there is barely any data and that's the main reson for a low score.
They pay cash and have little to no credit - and a low score, because the little information that is on file is negative. They simply lack all the positive entries that you get from paying a car loan and credit card one time - they simply own their car free and clear and have no credit card..
Our soft criteria are: neat and clean, a sense of personal responsibility, easy to talk to, calm and leavel headed - I look at these equally important as the hard criteria you have mentioned.