"Code" is another word for "law." Something does not become "code," until some governmental agency (Federal, State, County, City, or other) adopts it as being law within their jurisdiction. So the fact that the National Fire Protection Agency prints a new book called the 2005 National Electrical Code does not, by itself, cause that book to become law anywhere. For example, I believe that the state of Washington adopted the 2005 NEC into law effective July of last year. Up to that moment, the 2002 NEC was law in Washington.