calsd aclsd clasd lcasd alcsd lacsd casld acsld csald scald ascld sacld clsad lcsad cslad sclad lscad slcad alscd lascd aslcd salcd lsacd slacd calds aclds clads lcads alcds lacds cadls acdls cdals dcals adcls dacls cldas lcdas cdlas dclas ldcas dlcas aldcs ladcs adlcs dalcs ldacs dlacs casdl acsdl csadl scadl ascdl sacdl cadsl acdsl cdasl dcasl adcsl dacsl csdal scdal cdsal dcsal sdcal dscal asdcl sadcl adscl dascl sdacl dsacl clsda lcsda cslda sclda lscda slcda cldsa lcdsa cdlsa dclsa ldcsa dlcsa csdla scdla cdsla dcsla sdcla dscla lsdca sldca ldsca dlsca sdlca dslca alsdc lasdc asldc saldc lsadc sladc aldsc ladsc adlsc dalsc ldasc dlasc asdlc sadlc adslc daslc sdalc dsalc lsdac sldac ldsac dlsac sdlac dslac
Note: these 'words' (valid or invalid) are all the permutations of the word calsd. These words are obtained by scrambling the letters in calsd.