It seems that users are still using the code-challenge tag for challenge-oriented questions that do not correspond to the site's occasional voted-upon challenges. We already have the programming-challenge tag for off-site challenge programs, but it's understandable that the two tags sound similar.
So, I propose that we rename this tag in a way that it will not be confused with the other, while still communicating its purpose. If anyone has any ideas, please provide them.