Alphanumeric characters and spaces only, case-sensitive, maximum 32 characters. Choose a good username, because it will follow you around like a shadow until the sun goes dark and all life, all history, all that ever mattered is gone. If your username is awful - IE it contains hate speech, lovingly detailed descriptions of bodily functions, or other things that make people roll their eyes and say "Oh come on, Internet" - your account will be flushed away.
You'll have to click on a link to verify your email before you can log in. You'll only receive emails from Rook Trader regarding things that actually affect you. We don't sell or give away your email address - we just carefully write it out on a piece of parchment, set it briefly aflame, and eat it.
Enter the same email address again, because people often mistype a dot as a comma on touchscreens or whatever, and there's nothing worse than waiting for a verification email that doesn't come, and isn't going to come, because it's gone to firstname.lastname@example.org rather than email@example.com, and the dusty half-formed creature who owns firstname.lastname@example.org now has one more piece of information about you, one more piece that can help make your replacement go unnoticed when they come for you in the middle of the night. "Yes," your simulacrum will say to your peers, "It is definitely me. I signed up on a website to pretend to be a capitalist bird. That is what humans do. Humans just like me."
This minor inconvenience foils your replicant's plans. Type your email address very, very carefully.
Type the same password again, so you can be sure you entered it correctly the first time. Although you really, really should have entered it correctly the first time. Passwords are secrets. Never type these words into any other website. Never write them down. Never tell a soul. Promise me.