itsod tisod istod sitod tsiod stiod itosd tiosd iotsd oitsd toisd otisd isotd siotd iostd oistd soitd ositd tsoid stoid tosid otsid sotid ostid itsdo tisdo istdo sitdo tsido stido itdso tidso idtso ditso tdiso dtiso isdto sidto idsto disto sdito dsito tsdio stdio tdsio dtsio sdtio dstio itods tiods iotds oitds toids otids itdos tidos idtos ditos tdios dtios iodts oidts idots diots odits doits todis otdis tdois dtois odtis dotis isodt siodt iosdt oisdt soidt osidt isdot sidot idsot disot sdiot dsiot iodst oidst idost diost odist doist sodit osdit sdoit dsoit odsit dosit tsodi stodi tosdi otsdi sotdi ostdi tsdoi stdoi tdsoi dtsoi sdtoi dstoi todsi otdsi tdosi dtosi odtsi dotsi sodti osdti sdoti dsoti odsti dosti
Note: these 'words' (valid or invalid) are all the permutations of the word itsod. These words are obtained by scrambling the letters in itsod.