rules urles rlues lrues ulres lures ruels urels reuls eruls uerls eurls rleus lreus relus erlus lerus elrus ulers luers uelrs eulrs leurs elurs rulse urlse rluse lruse ulrse lurse rusle ursle rsule srule usrle surle rlsue lrsue rslue srlue lsrue slrue ulsre lusre uslre sulre lsure slure ruesl uresl reusl erusl uersl eursl rusel ursel rsuel sruel usrel surel resul ersul rseul sreul esrul serul uesrl eusrl userl suerl esurl seurl rlesu lresu relsu erlsu lersu elrsu rlseu lrseu rsleu srleu lsreu slreu reslu erslu rselu srelu esrlu serlu lesru elsru lseru sleru eslru selru ulesr luesr uelsr eulsr leusr elusr ulser luser usler suler lsuer sluer ueslr euslr uselr suelr esulr seulr lesur elsur lseur sleur eslur selur
Note: these 'words' (valid or invalid) are all the permutations of the word rules. These words are obtained by scrambling the letters in rules.