duffs udffs dfufs fdufs ufdfs fudfs duffs udffs dfufs fdufs ufdfs fudfs dffus fdfus dffus fdfus ffdus ffdus uffds fufds uffds fufds ffuds ffuds dufsf udfsf dfusf fdusf ufdsf fudsf dusff udsff dsuff sduff usdff sudff dfsuf fdsuf dsfuf sdfuf fsduf sfduf ufsdf fusdf usfdf sufdf fsudf sfudf dufsf udfsf dfusf fdusf ufdsf fudsf dusff udsff dsuff sduff usdff sudff dfsuf fdsuf dsfuf sdfuf fsduf sfduf ufsdf fusdf usfdf sufdf fsudf sfudf dffsu fdfsu dffsu fdfsu ffdsu ffdsu dfsfu fdsfu dsffu sdffu fsdfu sfdfu dfsfu fdsfu dsffu sdffu fsdfu sfdfu ffsdu ffsdu fsfdu sffdu fsfdu sffdu uffsd fufsd uffsd fufsd ffusd ffusd ufsfd fusfd usffd suffd fsufd sfufd ufsfd fusfd usffd suffd fsufd sfufd ffsud ffsud fsfud sffud fsfud sffud
Note: these 'words' (valid or invalid) are all the permutations of the word duffs. These words are obtained by scrambling the letters in duffs.