[keycloak-user] Prevent Users from Modifying Certain Custom User Attributes

Hi - I have some custom user attributes that I want users to be able to modify. Others, though, I want to forbid since they are set at account creation via internal procedures. Does anybody know how to prevent users from being able to edit these attributes? It isn't enough to leave it out of the account template, since formulating the correct POST as the user will cause the attribute to be updated (whether I modified the itl template to include it or not). Thanks! Josh