cloff lcoff colff oclff locff olcff clfof lcfof cflof fclof lfcof flcof coflf ocflf cfolf fcolf ofclf foclf lofcf olfcf lfocf flocf oflcf folcf cloff lcoff colff oclff locff olcff clfof lcfof cflof fclof lfcof flcof coflf ocflf cfolf fcolf ofclf foclf lofcf olfcf lfocf flocf oflcf folcf clffo lcffo cflfo fclfo lfcfo flcfo clffo lcffo cflfo fclfo lfcfo flcfo cfflo fcflo cfflo fcflo ffclo ffclo lffco flfco lffco flfco fflco fflco coffl ocffl cfofl fcofl ofcfl focfl coffl ocffl cfofl fcofl ofcfl focfl cffol fcfol cffol fcfol ffcol ffcol offcl fofcl offcl fofcl ffocl ffocl loffc olffc lfofc flofc oflfc folfc loffc olffc lfofc flofc oflfc folfc lffoc flfoc lffoc flfoc ffloc ffloc offlc foflc offlc foflc ffolc ffolc
Note: these 'words' (valid or invalid) are all the permutations of the word cloff. These words are obtained by scrambling the letters in cloff.