butle ubtle btule tbule utble tuble bulte ublte blute lbute ulbte lubte btlue tblue bltue lbtue tlbue ltbue utlbe tulbe ultbe lutbe tlube ltube butel ubtel btuel tbuel utbel tubel buetl ubetl beutl ebutl uebtl eubtl bteul tbeul betul ebtul tebul etbul utebl tuebl uetbl eutbl teubl etubl bulet ublet bluet lbuet ulbet lubet buelt ubelt beult ebult ueblt eublt bleut lbeut belut eblut lebut elbut ulebt luebt uelbt eulbt leubt elubt btleu tbleu blteu lbteu tlbeu ltbeu btelu tbelu betlu ebtlu teblu etblu bletu lbetu beltu ebltu lebtu elbtu tlebu ltebu telbu etlbu letbu eltbu utleb tuleb ulteb luteb tlueb ltueb utelb tuelb uetlb eutlb teulb etulb uletb luetb ueltb eultb leutb elutb tleub lteub telub etlub letub eltub
Note: these 'words' (valid or invalid) are all the permutations of the word butle. These words are obtained by scrambling the letters in butle.