Is there a way to lock a field instance?
I want to prevent users from editing or deleting a given instance, but allow the field to be customizable elsewhere by the user. If I lock the field, it will do the former, but prevent the latter.
According to this Field API documentation, fields can be locked by setting
locked = TRUE in the field definition, but there is no corresponding
locked key for the instance definition.
I experimented by adding
locked = TRUE to my field instance definition, and while that removed the edit and delete links from the bundle types view, I can still edit and delete by visiting the appropriate url.