Hi\! The number one thing you need to write on Arbital is an invite code that gives you editing powers\. We're not handing these out yet, so the real first step is to go to Arbital\.com and sign up to be notified about Arbital's progress\. Our first target domain will be math, on the current plan \(because math results are usually the least controversial kinds of things there are, and our reputation system isn't finished yet\)\.
I had to read this sentence several times to parse it correctly. Consider s/you need to write on/before you can write on/