A popular statement made about the plumbing code is it is a book for the plumbing contractor. Of course, that statement isn’t true.
The plumbing code is adopted by a jurisdiction as the legal requirements for regulating plumbing systems. As such, the plumbing code is used by many more individuals than plumbers. This group includes the jurisdiction, plumbing inspector, developer, architect, plumbing engineer, plumbing contractor, the public, the owner and finally the attorneys. Do not discount the last one. If it’s a legal document, it is used in a court of law.