stail tsail satil astil tasil atsil stial tsial sital istal tisal itsal saitl asitl siatl isatl aistl iastl taisl atisl tiasl itasl aitsl iatsl stali tsali satli astli tasli atsli stlai tslai sltai lstai tlsai ltsai salti aslti slati lsati alsti lasti talsi atlsi tlasi ltasi altsi latsi stila tsila sitla istla tisla itsla stlia tslia sltia lstia tlsia ltsia silta islta slita lsita ilsta lista tilsa itlsa tlisa ltisa iltsa litsa sailt asilt sialt isalt aislt iaslt salit aslit slait lsait alsit lasit silat islat sliat lsiat ilsat lisat ailst ialst alist laist ilast liast tails atils tials itals aitls iatls talis atlis tlais ltais altis latis tilas itlas tlias ltias iltas litas ailts ialts alits laits ilats liats
Note: these 'words' (valid or invalid) are all the permutations of the word stail. These words are obtained by scrambling the letters in stail.