ctdor tcdor cdtor dctor tdcor dtcor ctodr tcodr cotdr octdr tocdr otcdr cdotr dcotr codtr ocdtr doctr odctr tdocr dtocr todcr otdcr dotcr odtcr ctdro tcdro cdtro dctro tdcro dtcro ctrdo tcrdo crtdo rctdo trcdo rtcdo cdrto dcrto crdto rcdto drcto rdcto tdrco dtrco trdco rtdco drtco rdtco ctord tcord cotrd octrd tocrd otcrd ctrod tcrod crtod rctod trcod rtcod cortd ocrtd crotd rcotd orctd roctd torcd otrcd trocd rtocd ortcd rotcd cdort dcort codrt ocdrt docrt odcrt cdrot dcrot crdot rcdot drcot rdcot cordt ocrdt crodt rcodt orcdt rocdt dorct odrct droct rdoct ordct rodct tdorc dtorc todrc otdrc dotrc odtrc tdroc dtroc trdoc rtdoc drtoc rdtoc tordc otrdc trodc rtodc ortdc rotdc dortc odrtc drotc rdotc ordtc rodtc
Note: these 'words' (valid or invalid) are all the permutations of the word ctdor. These words are obtained by scrambling the letters in ctdor.