▁also ▁the ▁most ▁common ▁exclus ively ▁East ▁Asian ▁surname . ▁It ▁is ▁ranked ▁ 1 2 4 th ▁in ▁the ▁U . S . ▁Social ▁Security ▁Index . ▁ ▁Sub famil ies ▁ ▁In ▁Vietnam ese ▁tradition , ▁people ▁are ▁referred ▁to ▁by ▁their ▁personal ▁names ▁and ▁not ▁by ▁their ▁family ▁names ▁even ▁in ▁formal ▁situations . ▁Thus , ▁there ▁is ▁not ▁as ▁much ▁confusion ▁about ▁who ▁is ▁being ▁referred ▁to ▁as ▁one ▁might ▁expect . ▁However , ▁some ▁groups ▁distinguish ▁themselves ▁from ▁other ▁N gu y ễ n ▁by ▁passing ▁elements ▁of ▁their ▁names ▁that ▁are ▁usually ▁considered ▁middle ▁names ▁to ▁their ▁children . ▁This ▁practice ▁is ▁more ▁common ▁with ▁male ▁than ▁with ▁female ▁children . ▁Some ▁of ▁the ▁prominent ▁sub groups ▁within ▁the ▁N gu y ễ n ▁family ▁are , ▁in ▁no ▁particular ▁order : ▁N gu y ễ n ▁Ph ư ớ c ▁or ▁N gu y ễ n ▁Ph ú c : ▁S urname ▁for ▁the ▁N gu y ễ n ▁L ords ▁family ▁members , ▁and ▁all ▁members ▁of ▁the ▁N gu y ễ n ▁dynast y ▁em per ors . ▁N gu y ễ n ▁ Đ ì n h ▁N gu y ễ n ▁H ữ u ▁N gu y ễ n ▁C ả n h ▁N gu y ễ n ▁Kh ắ c ▁N gu y ễ n ▁Ti ế n ▁N gu y ễ n ▁ Đ ứ c ▁N gu y ễ n ▁Min h ▁N gu y ễ n ▁Ng ọ