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I tried editing my display name and for some names it gives me this error:

Display Name can only contain a-z, 0-9, spaces, apostrophes or hyphens and must start with a letter or number

That is clearly not the case, because it will take the following names:

  • NullUserException -龍-
  • NullUserException Ω
  • NullUserException ఠ_ఠ
  • NullUserException ಠ_ಠ
  • NullUserException இ_இ

But it won't let me do:

  • NullUserException (╯°o°)╯
  • NullUserException ٩๏̯͡๏)۶
  • NullUserException ☜(゚ヮ゚☜)
  • NullUserException อ้_อ้

So what's the regex used (assuming that's what's being used), so I can try out allowed names without actually changing it?

share|improve this question
Yeah, I tried changing my name to the guy flipping the table over and it didn't work for me either. If you can't have an ascii guy flipping a table over as your username what is the whole point of the site anyway? – Adam Davis Sep 15 '11 at 23:46
I saw "NullUserException ヮ゚" for your username when viewing this from the front page. – Andrew Grimm Sep 15 '11 at 23:46
@Andrew It's because I've been messing with my display name – NullUserException อ_อ Sep 15 '11 at 23:47
How did you manage to try out all the valid user names without running into the 30-day limit? – Pëkka Sep 16 '11 at 8:34
@Pekka - you can change it on each site and then copy the name to all the other sites. – ChrisF Sep 16 '11 at 9:21
@ChrisF yeah, I forgot. That was probably how he did it. – Pëkka Sep 16 '11 at 9:26
@Pekka It actually lets me try out a bunch of different display names. I think there's a kind of "grace period" where I can change the name as many times as I want – NullUserException อ_อ Sep 16 '11 at 13:59
Try this one - ノ'o'ノ丄丄 – o̊ǝʇ̲ ɐW⃗ Feb 14 '15 at 23:33
up vote 12 down vote accepted

a-z includes unicode characters, the way we define it.

So essentially the character set that maps to \w in a .NET regex.

share|improve this answer
You have an... interesting... definition of a-z. May I suggest "alphanumeric characters", or "letters, numbers, or..."? – Michael Petrotta Sep 16 '11 at 5:07
They made one of the classical Unicode Regex errors!!! Now we should try finding a numeric field and writing ৩০ for the age!!! (it's 30 in Bengali Digits. \d will conside them digits, Int32.Parse won't) – xanatos Sep 16 '11 at 8:41
@MichaelPetrotta status-completed – Matthew Read Sep 16 '11 at 15:38
May I respectfully request that it follow the Unicode Consortium’s recommendation of the \w definition of word characters according to Annex C of UTS #18 on Unicode Regular Expressions? Also, what is the length restriction in characters? – tchrist Aug 11 '12 at 0:40

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