How can I Prevent Users from Changing their Display Names?

[bcr123psu]

I'm using SMF 1.1.11 and would like to restrict permissions so that the users don't have the ability to change their display names, but I didn't see an option for this.  Anybody have any ideas on how I can do this?

Thanks!

[Illori]

check under admin > features and options

[bcr123psu]

Duh.  THANKS!