No, it means people on the thread can't date other people on the thread. If you do, both of you leave.
Basically, several people approached other people on here via PM. Some people got uncomfortable. Last year or the year before, some guy was meeting up with women from here, in a couple of cases (I think) things went further.
People on here are vulnerable, and can be seen as targets to others.
I started it, because someone was coming on a bit too strong to me via PMs, and I thought it was easier to just make the rule. Whenever people have dabbled, it's led to recriminations and name calling on here (not by or to me)
I've met quite a few former thread members. I'm good friends with some, in real life. One took their kids for a holiday at my place overseas when I wasn't there, another has invited me to her wedding later this year. my kids have played with the kids of another. These virtual things have a way of leaking out into the real world, which is as it should be.
But you don't date the thread. If you do, you both have to leave. That's only fair to everyone else. No one else should be dragged into arguments about who said what to whom. It's meant to be a safe place.