The test is whether you use that pseudonym in real life, where "real life" generally means "not the Internet". Note that there's an implicit judgement here that online interactions are fundamentally different from offline ones, which might not necessarily be accurate, but that's been part of Facebook's approach to social networking from day one.
I have no idea how'd you actually enforce this though. I can't think of a robust way to tell whether "Star-Lord" is how you introduce yourself on a first date or just your preferred pseudonym while playing video games.
Anecdotally, I picked up the nickname "Lizard" from friends well before I started using it online.
During my first year or so of college there were several people who admit to only having known me as "Lizard" as that was just how some friends introduced us. Facebook was still fairly new and small then so (I don't believe) there were many people trying to find "Lizard" on Facebook, but aside from a comment in my About (which would only help after they already found me) there was no reference to the only name some people knew me by.
I don't use the nickname offline much any more (though it's useful in busy restaurants to avoid confusion with other people who share my real name, and can prompt some interesting stories or conversations too) and I'm fairly certain the people I still interact with offline all know my real name.
Would/Should Facebook accept this nickname? Still? It doesn't really matter to me any more as I'd just assume be able to keep separate identities unless I want someone to know both. But for some people this nickname is synonymous with my real name and I will respond equivalently to either.
> Note that there's an implicit judgement here that online interactions are fundamentally different from offline ones, which might not necessarily be accurate, but that's been part of Facebook's approach to social networking from day one.
I think that what actually happened was that Facebook impressive feat was that is was able to merge the two — and wants to keep representing relations that have depth. I dislike the use of the word “real” for those, but it corresponds to a easy to sort judgement.
The fact that we have only one word to split the two: 'pseudonymous' explains the discrepancy mention above you. Yishang Wong made great points about that on Quora a while ago. “Snoop Dog” or “Sister Roma“ are established nom-de-scene, “phreak2345” is a temporary handle.
I have no idea how'd you actually enforce this though. I can't think of a robust way to tell whether "Star-Lord" is how you introduce yourself on a first date or just your preferred pseudonym while playing video games.