I don't really know how to explain this, so this will most probably not make much sense.
Basically, I made a custom field (drop-down selection) for the Add/Edit User page, and I want to be the only one who can edit this. Like... when users go to the Edit User page, they can change the value of this field, which I don't want them to be able to do. I would at least like this field to be invisible to them, but not completely disappear, as I still do need this field.