swerf wserf sewrf eswrf wesrf ewsrf swref wsref srwef rswef wrsef rwsef serwf esrwf srewf rsewf erswf reswf wersf ewrsf wresf rwesf erwsf rewsf swefr wsefr sewfr eswfr wesfr ewsfr swfer wsfer sfwer fswer wfser fwser sefwr esfwr sfewr fsewr efswr feswr wefsr ewfsr wfesr fwesr efwsr fewsr swrfe wsrfe srwfe rswfe wrsfe rwsfe swfre wsfre sfwre fswre wfsre fwsre srfwe rsfwe sfrwe fsrwe rfswe frswe wrfse rwfse wfrse fwrse rfwse frwse serfw esrfw srefw rsefw ersfw resfw sefrw esfrw sferw fserw efsrw fesrw srfew rsfew sfrew fsrew rfsew frsew erfsw refsw efrsw fersw rfesw fresw werfs ewrfs wrefs rwefs erwfs rewfs wefrs ewfrs wfers fwers efwrs fewrs wrfes rwfes wfres fwres rfwes frwes erfws refws efrws ferws rfews frews
Note: these 'words' (valid or invalid) are all the permutations of the word swerf. These words are obtained by scrambling the letters in swerf.