sefer esfer sfeer fseer efser feser seefr esefr seefr esefr eesfr eesfr sfeer fseer sefer esfer feser efser efesr feesr eefsr eefsr feesr efesr sefre esfre sfere fsere efsre fesre serfe esrfe srefe rsefe ersfe resfe sfree fsree srfee rsfee frsee rfsee efrse ferse erfse refse frese rfese seerf eserf seerf eserf eesrf eesrf seref esref sreef rseef ersef resef seref esref sreef rseef ersef resef eersf eersf eresf reesf eresf reesf sfere fsere sefre esfre fesre efsre sfree fsree srfee rsfee frsee rfsee serfe esrfe srefe rsefe ersfe resfe ferse efrse frese rfese erfse refse efers feers eefrs eefrs feers efers efres feres erfes refes frees rfees eerfs eerfs erefs reefs erefs reefs feres efres frees rfees erfes refes
Note: these 'words' (valid or invalid) are all the permutations of the word sefer. These words are obtained by scrambling the letters in sefer.