wribs rwibs wirbs iwrbs riwbs irwbs wrbis rwbis wbris bwris rbwis brwis wibrs iwbrs wbirs bwirs ibwrs biwrs ribws irbws rbiws briws ibrws birws wrisb rwisb wirsb iwrsb riwsb irwsb wrsib rwsib wsrib swrib rswib srwib wisrb iwsrb wsirb swirb iswrb siwrb riswb irswb rsiwb sriwb isrwb sirwb wrbsi rwbsi wbrsi bwrsi rbwsi brwsi wrsbi rwsbi wsrbi swrbi rswbi srwbi wbsri bwsri wsbri swbri bswri sbwri rbswi brswi rsbwi srbwi bsrwi sbrwi wibsr iwbsr wbisr bwisr ibwsr biwsr wisbr iwsbr wsibr swibr iswbr siwbr wbsir bwsir wsbir swbir bswir sbwir ibswr biswr isbwr sibwr bsiwr sbiwr ribsw irbsw rbisw brisw ibrsw birsw risbw irsbw rsibw sribw isrbw sirbw rbsiw brsiw rsbiw srbiw bsriw sbriw ibsrw bisrw isbrw sibrw bsirw sbirw
Note: these 'words' (valid or invalid) are all the permutations of the word wribs. These words are obtained by scrambling the letters in wribs.