racks arcks rcaks craks acrks carks rakcs arkcs rkacs kracs akrcs karcs rckas crkas rkcas krcas ckras kcras ackrs cakrs akcrs kacrs ckars kcars racsk arcsk rcask crask acrsk carsk rasck arsck rsack srack asrck sarck rcsak crsak rscak srcak csrak scrak acsrk casrk ascrk sacrk csark scark raksc arksc rkasc krasc akrsc karsc raskc arskc rsakc srakc asrkc sarkc rksac krsac rskac srkac ksrac skrac aksrc kasrc askrc sakrc ksarc skarc rcksa crksa rkcsa krcsa ckrsa kcrsa rcska crska rscka srcka csrka scrka rksca krsca rskca srkca ksrca skrca cksra kcsra cskra sckra kscra skcra acksr caksr akcsr kacsr ckasr kcasr acskr caskr asckr sackr csakr scakr akscr kascr askcr sakcr ksacr skacr cksar kcsar cskar sckar kscar skcar
Note: these 'words' (valid or invalid) are all the permutations of the word racks. These words are obtained by scrambling the letters in racks.