trock rtock torck otrck rotck ortck trcok rtcok tcrok ctrok rctok crtok tocrk otcrk tcork ctork octrk cotrk roctk orctk rcotk crotk ocrtk cortk trokc rtokc torkc otrkc rotkc ortkc trkoc rtkoc tkroc ktroc rktoc krtoc tokrc otkrc tkorc ktorc oktrc kotrc roktc orktc rkotc krotc okrtc kortc trcko rtcko tcrko ctrko rctko crtko trkco rtkco tkrco ktrco rktco krtco tckro ctkro tkcro ktcro cktro kctro rckto crkto rkcto krcto ckrto kcrto tockr otckr tcokr ctokr octkr cotkr tokcr otkcr tkocr ktocr oktcr kotcr tckor ctkor tkcor ktcor cktor kctor ocktr coktr okctr koctr ckotr kcotr rockt orckt rcokt crokt ocrkt corkt rokct orkct rkoct kroct okrct korct rckot crkot rkcot krcot ckrot kcrot ockrt cokrt okcrt kocrt ckort kcort
Note: these 'words' (valid or invalid) are all the permutations of the word trock. These words are obtained by scrambling the letters in trock.