optho potho otpho topho ptoho tpoho ophto pohto ohpto hopto photo hpoto othpo tohpo ohtpo hotpo thopo htopo pthoo tphoo phtoo hptoo thpoo htpoo optoh potoh otpoh topoh ptooh tpooh opoth pooth oopth oopth pooth opoth otoph tooph ootph ootph tooph otoph ptooh tpooh potoh optoh topoh otpoh ophot pohot ohpot hopot phoot hpoot opoht pooht oopht oopht pooht opoht ohopt hoopt oohpt oohpt hoopt ohopt phoot hpoot pohot ophot hopot ohpot othop tohop ohtop hotop thoop htoop otohp toohp oothp oothp toohp otohp ohotp hootp oohtp oohtp hootp ohotp thoop htoop tohop othop hotop ohtop pthoo tphoo phtoo hptoo thpoo htpoo ptoho tpoho potho optho topho otpho photo hpoto pohto ophto hopto ohpto thopo htopo tohpo othpo hotpo ohtpo
Note: these 'words' (valid or invalid) are all the permutations of the word optho. These words are obtained by scrambling the letters in optho.