frock rfock forck ofrck rofck orfck frcok rfcok fcrok cfrok rcfok crfok focrk ofcrk fcork cfork ocfrk cofrk rocfk orcfk rcofk crofk ocrfk corfk frokc rfokc forkc ofrkc rofkc orfkc frkoc rfkoc fkroc kfroc rkfoc krfoc fokrc ofkrc fkorc kforc okfrc kofrc rokfc orkfc rkofc krofc okrfc korfc frcko rfcko fcrko cfrko rcfko crfko frkco rfkco fkrco kfrco rkfco krfco fckro cfkro fkcro kfcro ckfro kcfro rckfo crkfo rkcfo krcfo ckrfo kcrfo fockr ofckr fcokr cfokr ocfkr cofkr fokcr ofkcr fkocr kfocr okfcr kofcr fckor cfkor fkcor kfcor ckfor kcfor ockfr cokfr okcfr kocfr ckofr kcofr rockf orckf rcokf crokf ocrkf corkf rokcf orkcf rkocf krocf okrcf korcf rckof crkof rkcof krcof ckrof kcrof ockrf cokrf okcrf kocrf ckorf kcorf
Note: these 'words' (valid or invalid) are all the permutations of the word frock. These words are obtained by scrambling the letters in frock.