The Quality Assurance check named ATC006 (AllTables/CrossTable/"Any fields not coded as coding lists on the table definition") I think needs to be more specific for the field being tested.
I was sitting with the DAD checks for the ART table– and we test both ART_RS and ART_ID for valid codes according to the table definitions. If a given record fails at least one of these checks then the error code ‘ATC006’ would not indicate which field failed.
Perhaps it could be named ATC006_<fieldname> or something - or some other way of indicating we are talking of wrong code according to the table def. I think this could need further discussion.