▁to ▁a ▁May ▁ 3 , ▁ 1 9 6 6 ▁mem o ▁from ▁T OS ▁producer ▁Robert ▁H . ▁Just man ▁to ▁Gene ▁Rod den berry ▁( l ater ▁repr int ed ▁in ▁the ▁book ▁The ▁M aking ▁of ▁Star ▁Tre k ) ▁in ▁which ▁Just man ▁recommended ▁that ▁all ▁V ul can ▁names ▁begin ▁with ▁" SP " ▁and ▁end ▁with ▁" K ", ▁and ▁have ▁exactly ▁five ▁letters . ▁( It ▁is ▁clear ▁from ▁the ▁context ▁of ▁the ▁book , ▁however , ▁that ▁the ▁mem o ▁was ▁intended ▁as ▁a ▁jo ke , ▁as ▁the ▁series ▁of ▁mem os ▁ends ▁up ▁discuss ing ▁the ▁pron unci ation ▁of ▁such ▁names ▁as ▁" S po ok ", ▁" Sp il k " ▁and ▁" Sp ork ". ) ▁ ▁Only ▁non - can on ical ▁sources ▁have ▁provided ▁any ▁V ul c ans ▁with ▁family ▁names , ▁which ▁are ▁usually ▁spoken ▁of ▁as ▁def ying ▁attempts ▁at ▁both ▁human ▁pron unci ation , ▁especially ▁with ▁English - language ▁ph on emes , ▁and ▁human ▁types et ting , ▁especially ▁with ▁the ▁characters ▁of ▁the ▁modern ▁Latin ▁alphabet ▁used ▁for ▁the ▁English ▁language . ▁Hence , ▁no ▁canonical ▁source ▁has ▁given ▁any ▁family ▁names ▁to ▁any ▁V ul can ▁characters , ▁and ▁indeed , ▁every ▁one ▁of ▁the ▁personal ▁names ▁previously ▁mentioned ▁are ▁all ▁officially ▁described ▁as ▁being ▁only ▁Latin - al phabet ical ▁and ▁English - phon etic ▁approxim ations ▁of ▁the ▁real ▁ones . ▁In ▁the ▁T OS ▁episode ▁"