However no universal written code existed before the 19th Century.

A strict code of conduct exists for federal judges, guiding their behavior.

Still, code exists, so if they haven't tried to start everything over from the beginning, a working implementation could be pretty quick to start up.

In fact, no generally recognized code of world criminal law has ever existed, strictly speaking.

A code of practice already exists for newsagents and retailers.

He's triggered all the overrides, using codes he shouldn't even have known existed.

Some were disappointed to learn that no such codes existed.

Standard national and international codes exist for many of these but are subject to revision every few years.

It is precisely because such a code does not exist, that we live in a period of uncertainty and experimentation.

If the code exists in only one place, then it can be easily changed there.