It seems several users have had their name changed after the migration to something default of the form "userNNNN": see for instance

https://mathoverflow.net/users/1784/user1784 (VA) https://mathoverflow.net/users/2349/user2349 (algori) https://mathoverflow.net/users/6451/user6451 (?)

  • $\begingroup$ The third one's called BS, looking at comment replies. $\endgroup$ Commented Jun 26, 2013 at 8:23
  • $\begingroup$ I'm checking on this now. $\endgroup$
    – Tim Post
    Commented Jun 26, 2013 at 9:07

1 Answer 1


This is due to two specific changes from the 1.0 engine to the 2.0 engine.

The first is that the minimum length of display names on the SE 2.0 engine is now three characters, not two. Names shorter than two characters were normalized in the pattern of user{user_id}. This is something they can change by editing their profile.

The second is that the engine no longer infers a username from OpenID. If you want anything other than the standard normalized user{user_id}, you need to deliberately set it. Accounts where one had been inferred were automatically changed to that effect. Again, the owners of those accounts are free to make the change.

Note - the system will only allow you to change your username once every 30 days. If someone affected by this were to make a mistake while changing their name back and need help correcting it, we're happy to do so.

I think this is the only other account related quirk as a direct result of the transition, but it's possible that others may come up. If they do, please continue to raise them here so we get them documented and folks encountering them find help :)

  • 2
    $\begingroup$ Would it be possible to generate a list of users with very short names who were renamed as a result of this? I'd be happy to contact the active users who were affected by this directly to explain what we've done to them. $\endgroup$ Commented Jun 26, 2013 at 15:40
  • $\begingroup$ I would suggest padding VA (and FC and any others) with a period, as described at meta.stackexchange.com/questions/106200/… . I hope we don't get a four character minimum; whatever would JSE do? $\endgroup$ Commented Jun 26, 2013 at 20:01
  • 1
    $\begingroup$ @ScottMorrison I think that's possible, but I have to wait for some folks to get off a plane. I'll be in touch via email either way. $\endgroup$
    – Tim Post
    Commented Jun 26, 2013 at 20:35
  • $\begingroup$ It seems MO cannot see my gravatar or any of my other OpenID information. When I click "Change picture", it shows an image with pink shapes on it, but not the photograph of me that is available on stackoverflow.com. $\endgroup$
    – bobobobo
    Commented Aug 4, 2013 at 0:16

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