ybutt byutt yubtt uybtt buytt ubytt ybtut bytut ytbut tybut btyut tbyut yutbt uytbt ytubt tyubt utybt tuybt butyt ubtyt btuyt tbuyt utbyt tubyt ybutt byutt yubtt uybtt buytt ubytt ybtut bytut ytbut tybut btyut tbyut yutbt uytbt ytubt tyubt utybt tuybt butyt ubtyt btuyt tbuyt utbyt tubyt ybttu byttu ytbtu tybtu btytu tbytu ybttu byttu ytbtu tybtu btytu tbytu yttbu tytbu yttbu tytbu ttybu ttybu bttyu tbtyu bttyu tbtyu ttbyu ttbyu yuttb uyttb ytutb tyutb utytb tuytb yuttb uyttb ytutb tyutb utytb tuytb yttub tytub yttub tytub ttyub ttyub uttyb tutyb uttyb tutyb ttuyb ttuyb butty ubtty btuty tbuty utbty tubty butty ubtty btuty tbuty utbty tubty bttuy tbtuy bttuy tbtuy ttbuy ttbuy uttby tutby uttby tutby ttuby ttuby
Note: these 'words' (valid or invalid) are all the permutations of the word ybutt. These words are obtained by scrambling the letters in ybutt.