I would tend to go with ProjectOfficial or project-official next.

I would not want to use the _ character as users tend to not remember that and there may be times you’re telling people and they’re not reading something and there’s also the fact that some people may see something and not do it immediately and rely on memory. There’s been a lot of research and experience in the digital marketing world that makes clear that web domains with underscores and dashes are not desirable. They’re just not well retained by people.

If you’re going with the above choices only, I would definitely go with the first choice because it is the standard for many artists, so relying on a standard practice makes it appear more professional and is more easily retained.

Got it, no pressing enter while typing without pressing shift, too. And edit doesn’t work on Firefox, it seems.

Anyway, like I was saying, I was focusing more on the suffix, but I suppose I should consider the separator, too. The “official” feels like something that big names use when there are dozens of unofficial accounts. It also feels like I was signing my own proof of identity. “It’s really me, honest!”.

Some platforms ignore the case of letters, and ex-Twitter for example accepts only underscores, though they distinguish case. I think it would be best to have identical username on all platforms, if possible, so that’s why the underscore as a separator was my first thought.

Generally they say to avoid the underscore, and also the dot. RealProject would be another good alternative. Only 4 extra characters, looks professional and generic if Project switches to something else so it will still work. Character length is an issue on some platforms, like Twitter allows only 16, if your like say ProjectSeven that’s already 12 characters so you only have 4 left. Another alternative is to target the domain, if you have that or will have it. Like ProjectCom, ProjectNet, etc.