trest rtest terst etrst retst ertst trset rtset tsret stret rstet srtet tesrt etsrt tsert stert estrt setrt restt erstt rsett srett esrtt sertt trets rtets terts etrts retts ertts trtes rttes ttres ttres rttes trtes tetrs ettrs tters tters ettrs tetrs retts ertts rtets trets etrts terts trste rtste tsrte strte rstte srtte trtse rttse ttrse ttrse rttse trtse tstre sttre ttsre ttsre sttre tstre rstte srtte rtste trste strte tsrte testr etstr tsetr stetr esttr settr tetsr ettsr ttesr ttesr ettsr tetsr tster stter ttser ttser stter tster esttr settr etstr testr stetr tsetr restt erstt rsett srett esrtt sertt retst ertst rtest trest etrst terst rstet srtet rtset trset stret tsret estrt setrt etsrt tesrt stert tsert
Note: these 'words' (valid or invalid) are all the permutations of the word trest. These words are obtained by scrambling the letters in trest.