until nutil utnil tunil ntuil tnuil unitl nuitl uintl iuntl niutl inutl utinl tuinl uitnl iutnl tiunl itunl ntiul tniul nitul intul tinul itnul untli nutli utnli tunli ntuli tnuli unlti nulti ulnti lunti nluti lnuti utlni tulni ultni lutni tluni ltuni ntlui tnlui nltui lntui tlnui ltnui unilt nuilt uinlt iunlt niult inult unlit nulit ulnit lunit nluit lnuit uilnt iulnt ulint luint ilunt liunt nilut inlut nliut lniut ilnut linut utiln tuiln uitln iutln tiuln ituln utlin tulin ultin lutin tluin ltuin uiltn iultn ulitn luitn ilutn liutn tilun itlun tliun ltiun iltun litun ntilu tnilu nitlu intlu tinlu itnlu ntliu tnliu nltiu lntiu tlniu ltniu niltu inltu nlitu lnitu ilntu lintu tilnu itlnu tlinu ltinu iltnu litnu
Note: these 'words' (valid or invalid) are all the permutations of the word until. These words are obtained by scrambling the letters in until.