SELECT DISTINCT hwcompatibility.hwcompatibility_item_number AS item, item.item_descrip1 AS title, item.item_descrip2 AS specification
  FROM mpe.hwcompatibility
    JOIN mpe.hwcompatibilitynotes ON hwcompatibilitynotes.hwcompatibilitynotes_hwcompatibility_association = hwcompatibility.hwcompatibility_association
    JOIN public.item ON item_number = hwcompatibility.hwcompatibility_item_number
 ORDER BY hwcompatibility.hwcompatibility_item_number