rfavn fravn rafvn arfvn farvn afrvn rfvan frvan rvfan vrfan fvran vfran ravfn arvfn rvafn vrafn avrfn varfn favrn afvrn fvarn vfarn avfrn vafrn rfanv franv rafnv arfnv farnv afrnv rfnav frnav rnfav nrfav fnrav nfrav ranfv arnfv rnafv nrafv anrfv narfv fanrv afnrv fnarv nfarv anfrv nafrv rfvna frvna rvfna vrfna fvrna vfrna rfnva frnva rnfva nrfva fnrva nfrva rvnfa vrnfa rnvfa nrvfa vnrfa nvrfa fvnra vfnra fnvra nfvra vnfra nvfra ravnf arvnf rvanf vranf avrnf varnf ranvf arnvf rnavf nravf anrvf narvf rvnaf vrnaf rnvaf nrvaf vnraf nvraf avnrf vanrf anvrf navrf vnarf nvarf favnr afvnr fvanr vfanr avfnr vafnr fanvr afnvr fnavr nfavr anfvr nafvr fvnar vfnar fnvar nfvar vnfar nvfar avnfr vanfr anvfr navfr vnafr nvafr
Note: these 'words' (valid or invalid) are all the permutations of the word rfavn. These words are obtained by scrambling the letters in rfavn.