yirds iyrds yrids ryids iryds riyds yidrs iydrs ydirs dyirs idyrs diyrs yrdis rydis ydris dyris rdyis dryis irdys ridys idrys dirys rdiys driys yirsd iyrsd yrisd ryisd irysd riysd yisrd iysrd ysird syird isyrd siyrd yrsid rysid ysrid syrid rsyid sryid irsyd risyd isryd siryd rsiyd sriyd yidsr iydsr ydisr dyisr idysr diysr yisdr iysdr ysidr syidr isydr siydr ydsir dysir ysdir sydir dsyir sdyir idsyr disyr isdyr sidyr dsiyr sdiyr yrdsi rydsi ydrsi dyrsi rdysi drysi yrsdi rysdi ysrdi syrdi rsydi srydi ydsri dysri ysdri sydri dsyri sdyri rdsyi drsyi rsdyi srdyi dsryi sdryi irdsy ridsy idrsy dirsy rdisy drisy irsdy risdy isrdy sirdy rsidy sridy idsry disry isdry sidry dsiry sdiry rdsiy drsiy rsdiy srdiy dsriy sdriy
Note: these 'words' (valid or invalid) are all the permutations of the word yirds. These words are obtained by scrambling the letters in yirds.