Absolutely nothing- which is why I personally don't put too much stock in THIS kind of listing. Referring to my post above, it depends on the good will of the membership.
A better process would be to check the web site of a particular style to see if there is an affiliated school in your area or a commercial listing such as the Better Business Bureau in the area where I live. These kinds of listings can tell you if there are any business problems with the school not delivering on contracts etc.
I found my present school by interviewing schools. After having been in one martial art for a few years, I knew what kinds of questions I wanted to ask and what answers I needed. I was happy with my choice.
I think a newbie to martial arts would be well served to interview around and to attend the free class(es) that a prospective student is allowed to take and pick a school that way and preferably with a friend.
Sometimes it isn't a school style, but the age of the students, the "personality teaching style" of the instructors, location and other factors that end up being more important.
The older I get, the better I was!