Iingcango zomlilo zahlulwe zibe ziingcango zomlilo eziqhelekileyo ezivulekileyo kwaye ngokuqhelekileyo zivaliwe iingcango zomlilo. Ngokuqhelekileyo iingcango zomlilo ezivulekileyo zigcinwa zivuliwe ngamaxesha aqhelekileyo kwaye zisetyenziselwa ukudlula. Ngokuqhelekileyo iminyango yomlilo evaliweyo inokuthintela ngokufanelekileyo ukuhlasela komsi kunye nomlilo emva komlilo, ngoko ke enye yemilinganiselo ebalulekileyo yokukhusela umlilo.