ratch artch rtach trach atrch tarch racth arcth rcath crath acrth carth rtcah trcah rctah crtah tcrah ctrah atcrh tacrh actrh catrh tcarh ctarh rathc arthc rtahc trahc atrhc tarhc rahtc arhtc rhatc hratc ahrtc hartc rthac trhac rhtac hrtac thrac htrac athrc tahrc ahtrc hatrc tharc htarc racht archt rcaht craht acrht carht rahct arhct rhact hract ahrct harct rchat crhat rhcat hrcat chrat hcrat achrt cahrt ahcrt hacrt chart hcart rtcha trcha rctha crtha tcrha ctrha rthca trhca rhtca hrtca thrca htrca rchta crhta rhcta hrcta chrta hcrta tchra cthra thcra htcra chtra hctra atchr tachr acthr cathr tcahr ctahr athcr tahcr ahtcr hatcr thacr htacr achtr cahtr ahctr hactr chatr hcatr tchar cthar thcar htcar chtar hctar
Note: these 'words' (valid or invalid) are all the permutations of the word ratch. These words are obtained by scrambling the letters in ratch.