src/main/java/com/conveyal/gtfs/loader/Table.java
public List<Field> editorFields() {
        List<Field> editorFields = new ArrayList<>();
        for (Field f : fields) if (f.requirement == REQUIRED || f.requirement == OPTIONAL || f.requirement == EDITOR) {
            editorFields.add(f);
        }
        return editorFields;
    }
public List<Field> editorFields() {
        List<Field> editorFields = new ArrayList<>();
        for (Field f : fields) if (f.requirement == REQUIRED || f.requirement == OPTIONAL || f.requirement == EDITOR) {
            editorFields.add(f);
        }
        return editorFields;
    }
Get only those fields included in the official GTFS specification for this table or used by the editor.