spifs psifs sipfs ispfs pisfs ipsfs spfis psfis sfpis fspis pfsis fpsis sifps isfps sfips fsips ifsps fisps pifss ipfss pfiss fpiss ifpss fipss spisf psisf sipsf ispsf pissf ipssf spsif pssif sspif sspif pssif spsif sispf isspf ssipf ssipf isspf sispf pissf ipssf psisf spisf ispsf sipsf spfsi psfsi sfpsi fspsi pfssi fpssi spsfi pssfi sspfi sspfi pssfi spsfi sfspi fsspi ssfpi ssfpi fsspi sfspi pfssi fpssi psfsi spfsi fspsi sfpsi sifsp isfsp sfisp fsisp ifssp fissp sisfp issfp ssifp ssifp issfp sisfp sfsip fssip ssfip ssfip fssip sfsip ifssp fissp isfsp sifsp fsisp sfisp pifss ipfss pfiss fpiss ifpss fipss pisfs ipsfs psifs spifs ispfs sipfs pfsis fpsis psfis spfis fspis sfpis ifsps fisps isfps sifps fsips sfips
Note: these 'words' (valid or invalid) are all the permutations of the word spifs. These words are obtained by scrambling the letters in spifs.