User Settings > Personal allows users to create invalid names

[RogerHaase]

1. Self-registration or command line registration checks the user name for invalid characters such as /, ,, :, etc.

But a logged-in user can change his name to an invalid name such as Joe/Doe by using the User Settings > Personnel dialog.

2. Related: docs do not mention that a user may create an alias name such as JoeDoe, jd; nor when an alias may be useful.

3. Related: missing feature? Moin 1.9.x had configure options to prevent users from changing their name or email:

# +++ these are suggested changes to the user preferences form if the  external_cookie  is the only auth method
user_form_disable = ['name', 'aliasname', 'email',] # don't let the user change these, but show them:
user_form_remove = ['aliasname', 'password', 'password2', 'css_url', 'logout', 'create', 'account_sendmail','jid'] # remove completely:

Ignore 3 above; moved to #1712.

4. Related: per docs:

Display-Name
 The display name can be used to override your username, 
 so you will still log in using your username
 but your display name will be displayed to other users 
 and in your history page.

The Display-Name is not shown in Global History, Item History, nor the footer. Instead the (first) username is displayed.

5. Related: The Admin > Users view should include Display Name.

6. Related: The docs do not mention that UserNames/DisplayNames are rendered as links to the users namespace.

[UlrichB22]

Flush error messages are only visible for a very short period of time and disappear without being clicked.
I had this problem already before this change in my environment.