How to add custom attributes in User creation view?
Accepted answer
The Jazz user artifact is not as flexible as the work item.
You will not be able to define custom attributes to User.
But the User Editor has the code extensions through which you can add new tabs and be able to do add anything you want there.
One other answer
This functionality is requested in work item It should be possible to add additional information to user profile (159453). Please feel free to add a comment to that work item to indicate your interest/support.