firev ifrev friev rfiev irfev rifev fierv iferv feirv efirv iefrv eifrv freiv rfeiv feriv efriv refiv erfiv irefv riefv ierfv eirfv reifv erifv firve ifrve frive rfive irfve rifve fivre ifvre fvire vfire ivfre vifre frvie rfvie fvrie vfrie rvfie vrfie irvfe rivfe ivrfe virfe rvife vrife fievr ifevr feivr efivr iefvr eifvr fiver ifver fvier vfier ivfer vifer fevir efvir fveir vfeir evfir vefir ievfr eivfr ivefr viefr evifr veifr frevi rfevi fervi efrvi refvi erfvi frvei rfvei fvrei vfrei rvfei vrfei fevri efvri fveri vferi evfri vefri revfi ervfi rvefi vrefi evrfi verfi irevf rievf iervf eirvf reivf erivf irvef rivef ivref viref rvief vrief ievrf eivrf iverf vierf evirf veirf revif ervif rveif vreif evrif verif
Note: these 'words' (valid or invalid) are all the permutations of the word firev. These words are obtained by scrambling the letters in firev.