Custom Fields - ability to reorder / move

At present Custom Fields cannot be reordered so if you subsequently add a new field it will sit at the bottom of the list but it might relate to one at the top end of the field list and would look better sitting below the linked one. The ability to reorder / move the fields in Settings would be useful to put linked fields next to each other. The only option that was suggested was to delete Custom Fields and then readd in the correct order but this would effect clients with data already logged in those fields. Thanks