α. Old English constungae (Mercian, accusative, transmission error), Old English costing, Old English costong (Northumbrian), Old English costuncg (Northumbrian), Old English–early Middle English costung, early Middle English costlinge (dative, apparently transmission error).
β. Old English costnuncg, Old English–early Middle English costnung, late Old English costnigna (Kentish, accusative, transmission error), late Old English costning, late Old English costnungen (accusative plural), early Middle English costneng- (inflected form), early Middle English costninȝ.