quod uqod qoud oqud uoqd ouqd qudo uqdo qduo dquo udqo duqo qodu oqdu qdou dqou odqu doqu uodq oudq udoq duoq oduq douq
Note: these 'words' (valid or invalid) are all the permutations of the word quod. These words are obtained by scrambling the letters in quod.