Custom Profile Fields

[Veronika]

I need to ban/disallow users from changing the "Custom Profile Fields" I have setup for them. This will be restricted Forum, all accounts will be created by admin. I cannot find a place where I can specify it.
They can change the other fields (password, username etc.)
Tx

[Jade Elizabeth]

Modify the field and edit the "Privacy: Who can see and edit this field." option in the advanced options section