# Unique user names?

Apparently user names don't have to be unique, see the comments to this answer. Was this a good idea? In the comments I mentioned it's only clear which Mark is which because one is the OP and hence has his name formatted differently. In other situations it may be harder to tell them apart.
Shouldn't we for future registrations stick to unique user names?

• This has always seemed like such a common practice to implement on any site that uses usernames. I always figured StackExchange must have had to intentionally not included this check, never made sense to me though. – Kellenjb Jul 1 '11 at 13:30
• @kellen I do not believe that only one person in the entire world (aka network) has the privilege and right to be called "Mark" – Jeff Atwood Jul 1 '11 at 19:35
• @Jeff Atwood I understand what you guys think, it just doesn't make sense to me. – Kellenjb Jul 1 '11 at 20:17
• @Jeff Atwood: I'm not sure you would be happy if somebody else registered as "Jeff Atwood", even if that would be his real name. In any case, I wouldn't like to have a second Federico Russo. Can only bring confusion. I know a girl whose email address is just <herFirstName>@gmail.com. Pity for those hundreds of thousands other girls with the same name, but they'll have to pick another name. My vote is against duplicates. – Federico Russo Jul 2 '11 at 15:16
• @Federico - Hey, I know that girl too! :-) – stevenvh Jul 2 '11 at 15:50
• @federico there is a special case around impersonating moderators with the intent to deceive, but in general it would be fine. For one thing, I have a certain rep level, diamond next to name, etc. There is more to a person than their name. (Also, there is peer pressure to be unique, is there not? And name changes are two clicks away) – Jeff Atwood Jul 2 '11 at 21:04
• @Jeff Atwood the problem I see with that is there has been no effort to let users know that their names aren't unique. The assumption is that they will be unique because that is how it is everywhere else on the web. – Kellenjb Jul 9 '11 at 18:37
• @Kellenjb - fact. but there are also users who don't seem to care about it. You don't pick a user name like mark hoping it will be unique. – stevenvh Jul 10 '11 at 1:58