ribes irbes rbies bries ibres bires riebs irebs reibs eribs ierbs eirbs rbeis breis rebis erbis beris ebris ibers biers iebrs eibrs beirs ebirs ribse irbse rbise brise ibrse birse risbe irsbe rsibe sribe isrbe sirbe rbsie brsie rsbie srbie bsrie sbrie ibsre bisre isbre sibre bsire sbire riesb iresb reisb erisb iersb eirsb riseb irseb rsieb srieb isreb sireb resib ersib rseib sreib esrib serib iesrb eisrb iserb sierb esirb seirb rbesi bresi rebsi erbsi bersi ebrsi rbsei brsei rsbei srbei bsrei sbrei resbi ersbi rsebi srebi esrbi serbi besri ebsri bseri sberi esbri sebri ibesr biesr iebsr eibsr beisr ebisr ibser biser isber siber bsier sbier iesbr eisbr isebr siebr esibr seibr besir ebsir bseir sbeir esbir sebir
Note: these 'words' (valid or invalid) are all the permutations of the word ribes. These words are obtained by scrambling the letters in ribes.