According to Osho, after Mahavira the 'code words' survived only as written terms; people knew the words but forgot they were ciphers—practical keys for inner work—and lost the method to apply them. They became dead records. Without a living master to decode them, their meditative use, context, and transmission vanished, leaving only misunderstood scripture.
People kept the secret passwords but forgot what door they open and how to use them.