To me, non-trad friendly means that there are students (plural!) over 30 attending the school, and that they consider non-trads over age 30 independent for institutional aid purposes. Naturally, I only have a select list because I didn't apply to or interview at every school in the country, but other people can feel free to add more to my lists if they want. I would broadly classify schools into three categories:
Some schools that have a lot of non-trads and are financially friendly to non-trads would include Miami, Baylor, Chicago, Pitt, UAB, and Yale. I would rate these schools as being very non-trad friendly. Pitt in particular even has an Old Fart's Club. 😉
Some schools that have a lot of non-trads but that do not consider non-trads independent for institutional aid are USF, Case, Cleveland Clinic, U Mich, AECOM, and Harvard. These schools are also non-trad friendly, but they're going to cost you big-time, which is not so nice for older non-trads who have parents with assets. If you are not a FL resident, don't waste your time applying to USF, because they take very few people from OOS.
Schools that do not have a lot of non-trads nor do they give non-trads independent institutional aid status include Wash U, UF, U Penn, Vanderbilt, and Duke. I wouldn't go as far as to say that non-trads shouldn't apply to or attend these schools, but if you're around age 30, you will almost certainly be the oldest person in your class, and you WILL have to provide them with your parents' financial info. These also tend to be very stat-driven schools in my experience.