When you create a new custom field on a standard object or a custom object, by default there is some FLS. (I mean for some profiles the Visible checkbox is checked and for some it is not.) How is that determined? It does not seem to match the object settings on the profile. Hence the question. Also for some fields Visible is checked on all profiles and I cannot even adjust it , as in I cannot uncheck the checkbox for any profiles. Can some one explain how FLS works?