How do anda make a back-up account?

Honestly, I don't think it's allowed, but many people do. It's not really a big deal. I think anda have to use a different email. Why do anda need one?

Ya, I think anda can, but they're highly discouraged. Also the F4 can tell from your IP address if anda have multiple accounts, and they can shut them down if they're being used just for ratings, atau if someone uses one to be outspoken on. I've seen people be banned for both uses.