UDF should be read-only but isn't. V2017. The UDF in AR Invoice Header is an alternate invoice #. I created the UDF as a Biz Obj in CR Detail. When I add the field to the CR Entry screen, it is not ""greyed out"" and can be modified, which is not what I want. I haven't been able to prevent access to it. Should the ""disable"" checkbox do that? By the way, I set it to disabled, but that didn't work, and every time I open the screen, it's unchecked again.