What is the reasoning behind the design decision to allow users to create a display name which matches another existing users exactly?

This is opposed to the common practice of enforcing unique user names, and I'd really like to learn something.

  • 1
    Tagged possible-dupe because you think this might be a dupe or is it about possible dupe display names?
    – random
    Commented Oct 10, 2009 at 14:18
  • I got a feeling the Q is a dupe, but I can't find it. Commented Oct 10, 2009 at 14:25
  • 3
    +1 . I think no one can answer this ( accurately ) but Jeff.
    – OscarRyz
    Commented Oct 10, 2009 at 19:01
  • Let the Davids flourish.
    – TRiG
    Commented Jan 17, 2014 at 11:57
  • The network handles users using their unique ID numbers. The username is just window dressing.
    – Vikki
    Commented Oct 11, 2019 at 6:00

6 Answers 6


People have the same names in real life. Isn't Stack Overflow real life?

  • 28
    What happens if the answer to your question is no?
    – tvanfosson
    Commented Oct 12, 2009 at 12:10
  • 5
    please don't ! :P
    – Cesar
    Commented May 3, 2010 at 0:49
  • 17
    No, it isn't real life, it is a computer system, and it is one where you can't see the faces or the handwriting of the people posting. Requiring unique names is an elementary security feature and a guard against misrepresentation. It astonishes me that SO doesn't take this elementary precaution and it appears to me to open up some nasty legal liability questions.
    – user207421
    Commented Feb 6, 2013 at 3:17
  • 11
    @EJP every user account has a unique ID number, so you cannot be impersonated totally Commented Feb 3, 2014 at 22:19

If they didn't, and people missed out on their first choice, you'd be left with trying to come up with all sorts of variations just to "be yourself".

You don't want it to be like AOL or Xbox Live (badges notwithstanding) where if you're not the first, you're docsavage1933 while some other joker, who just happens to be in before you gets to sit around on docsavage.

If someone wants to be known as, say Fletch, and another user happens to also be named Fletch, and both would rather go by that instead of changing and feeling like someone else or not truly expressive under their own name, how do you coordinate a fight to the death where the victor keeps their name?

  • 5
    how do you coordinate a fight to the death where the victor keeps their name? By making them answer 20 questions! Commented Nov 25, 2014 at 1:57

Anyone who wants to avoid having a duplicate name can always add "the Lizard" or some other creature to the end and get a unique name.


  • 35
    If you say so...
    – Vinko Vrsalovic StaffMod
    Commented Jan 15, 2010 at 20:43
  • 4
    See -- very unique.
    – tvanfosson
    Commented Jan 15, 2010 at 23:14

The ability to have any display name makes me uneasy. Particularly with comments - there's no convenient way to tell who has left a comment without clicking through to the user page. Most people will just assume you are who you appear to be, particularly if you're a well known user. Also, being able to change your display name at any time often leads to discontinuities when trying to follow the thread of a comment discussion, since the @user convention doesn't update in step.

It can be very confusing on those occasions where two users have chosen the same name. For example, on meta I have seen some perplexing discussions between identical users...

I've read the other responses, but I personally don't see the problem with unique names. Is having hundreds of users named 'joe' really any better than 'joe1', 'joe2' etc.? Do people really feel it's 'unfair' that their real name isn't available on Skype or Gmail anymore? Users seem to manage well enough on every other site/email address in existence...

  • 6
    Think about the implicit message we're sending here: if you want to be unique, then choose a unique name. If you don't, then don't. Commented Oct 11, 2009 at 5:03
  • 3
    Jeff, it's not black and white. E.g., what if comments had gravatars? Then you could tell duplicate names apart. Commented Oct 12, 2009 at 12:52

There are so many programmers participating in stackoverflow it would be unfair to reserve a name for the first one. Everyone should be able to use his own name.

Have you ever noticed how people choose their e-mail addresses?

In the end there's no reason not to allow everyone to choose their name freely. With unicode support enabled one could easily create a name that looked like another anyway.

  • 1
    Or you could use the same rules that IDN uses to prevent lookalike names.
    – binki
    Commented Dec 6, 2016 at 20:52

Not really an answer - but the user id is the unique part, the name is just the human (and possibly SEO) readable bit, so there's no need in the system for the name to be unique.

Obviously there are any number of "John Smith"'s or "Fred Bloggs"'s who are using their own name - which is as it should be. However, I've never come across a user who's tried to impersonate a high rep user by using their exact name (I've seen a couple of "jon_skeet"'s and even a "john skeet") but even if I did their reputation would give the game away, so I'd normally be 99% sure it's the right person.

Have you got any examples of where this has been done?

With regard to your system - if you had a "score" generated by the system and that was always displayed, it would be even rarer that the user you were trying to impersonate would have exactly the same score as you. On SO there are 4 values you'd have to match (pure rep, and nos of gold, silver and bronze badges).

  • 1
    No, my partner & I are designing an app. When we started discussing if we should allow multiple users with the exact same name, I told him SO has it and proved it by changing my name to his ... and it worked. So we were wondering if we should do it, and what we are not taking into account that SO obviously did. Commented Oct 10, 2009 at 14:28
  • We've changed and/or deleted several Jon Skeet's from the system on SO. There have been a few other cases of impersonation, but Jon seems to be the favorite target of such shenanigans. (Although I would guess Jeff and Joel get their fair share.) Commented Oct 10, 2009 at 15:09
  • 4
    The first four names I search for have exact matches: Rob (8), John (6), Jeff (5), David (9)... They probably shouldn't expect to be exclusive. Commented Oct 10, 2009 at 15:34
  • I notice there are 2 "jodrell" in superuser, probably the same person!?
    – HaveAGuess
    Commented Sep 17, 2013 at 20:32
  • I'm a little late to the party, but there are definitely (at least) two "frosty"s.
    – Trojan
    Commented Jan 12, 2014 at 21:10
  • 1
    There are thousands of exact name duplicates. I think you mean "intentionally impersonate a high rep user with a famous name" or something like that.
    – Caleb
    Commented Jan 17, 2014 at 9:55
  • @Caleb - indeed.
    – ChrisF Mod
    Commented Jan 17, 2014 at 10:36

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