rlisd lrisd rilsd irlsd lirsd ilrsd rlsid lrsid rslid srlid lsrid slrid risld irsld rsild srild isrld sirld lisrd ilsrd lsird slird islrd silrd rlids lrids rilds irlds lirds ilrds rldis lrdis rdlis drlis ldris dlris ridls irdls rdils drils idrls dirls lidrs ildrs ldirs dlirs idlrs dilrs rlsdi lrsdi rsldi srldi lsrdi slrdi rldsi lrdsi rdlsi drlsi ldrsi dlrsi rsdli srdli rdsli drsli sdrli dsrli lsdri sldri ldsri dlsri sdlri dslri risdl irsdl rsidl sridl isrdl sirdl ridsl irdsl rdisl drisl idrsl dirsl rsdil srdil rdsil drsil sdril dsril isdrl sidrl idsrl disrl sdirl dsirl lisdr ilsdr lsidr slidr isldr sildr lidsr ildsr ldisr dlisr idlsr dilsr lsdir sldir ldsir dlsir sdlir dslir isdlr sidlr idslr dislr sdilr dsilr
Note: these 'words' (valid or invalid) are all the permutations of the word rlisd. These words are obtained by scrambling the letters in rlisd.