kraft rkaft karft akrft rakft arkft krfat rkfat kfrat fkrat rfkat frkat kafrt akfrt kfart fkart afkrt fakrt rafkt arfkt rfakt frakt afrkt farkt kratf rkatf kartf akrtf raktf arktf krtaf rktaf ktraf tkraf rtkaf trkaf katrf aktrf ktarf tkarf atkrf takrf ratkf artkf rtakf trakf atrkf tarkf krfta rkfta kfrta fkrta rfkta frkta krtfa rktfa ktrfa tkrfa rtkfa trkfa kftra fktra ktfra tkfra ftkra tfkra rftka frtka rtfka trfka ftrka tfrka kaftr akftr kfatr fkatr afktr faktr katfr aktfr ktafr tkafr atkfr takfr kftar fktar ktfar tkfar ftkar tfkar aftkr fatkr atfkr tafkr ftakr tfakr raftk arftk rfatk fratk afrtk fartk ratfk artfk rtafk trafk atrfk tarfk rftak frtak rtfak trfak ftrak tfrak aftrk fatrk atfrk tafrk ftark tfark
Note: these 'words' (valid or invalid) are all the permutations of the word kraft. These words are obtained by scrambling the letters in kraft.