Can I know some nickname already exist?

@FriendlyFin I'm pretty sure you can use old usernames or slightly different versions of a username(ie, Ispace instead of iSPACE, or OrbITech001 instead of OrbITech), however, I haven't changed my username or tried to "copy" someone else's username, so I don't know for sure

Honestly, I'm not really sure how all that works here. I think you're correct that you can't use a name that's currently being used, but I think you can reuse old names since some users have switched back to older names they used. You could scroll through the Users tab on the site, but that would take a long time and not be very fun. You could also google search "SimpleRockets.com +(username)" and see if anything pops up there. I understand why you wouldn't want to use the same(or at least too similar) name as someone else, since I've had it happen to me(there's only so many combinations of words that make sense as a name, so similarity is unavoidable, but to actively copy someone else's name is not okay).

I really wish there was an internal search function for stuff like that...

you are capable of using someone else’s username only if you hack or get a really lucky glitch

so you don’t have to worry about using someone else’s username