berks ebrks breks rbeks erbks rebks bekrs ebkrs bkers kbers ekbrs kebrs brkes rbkes bkres kbres rkbes krbes erkbs rekbs ekrbs kerbs rkebs krebs bersk ebrsk bresk rbesk erbsk rebsk besrk ebsrk bserk sberk esbrk sebrk brsek rbsek bsrek sbrek rsbek srbek ersbk resbk esrbk serbk rsebk srebk beksr ebksr bkesr kbesr ekbsr kebsr beskr ebskr bsekr sbekr esbkr sebkr bkser kbser bsker sbker ksber skber eksbr kesbr eskbr sekbr ksebr skebr brkse rbkse bkrse kbrse rkbse krbse brske rbske bsrke sbrke rsbke srbke bksre kbsre bskre sbkre ksbre skbre rksbe krsbe rskbe srkbe ksrbe skrbe erksb reksb ekrsb kersb rkesb kresb erskb reskb esrkb serkb rsekb srekb eksrb kesrb eskrb sekrb kserb skerb rkseb krseb rskeb srkeb ksreb skreb
Note: these 'words' (valid or invalid) are all the permutations of the word berks. These words are obtained by scrambling the letters in berks.