Ya I was just making sure... rules seem to be changed a lot around here.
Well, it's impossible to come up with perfect rules without actually testing things in reality. For example signing up might sound like a great and organized way of doing this, but in reality it's a tedious and demanding task for organizers. In the end fails because people sign up "just in case" and never show up, basically giving the finger to people spend their free time running these things.
I'm pretty confident that the current rules will work because they are so simple. The more simple system we use, the less likely it is that it needs to be changed.