The main reason for a Professional Regulator to publish a Code of Ethics is to

NPPE materials explain that Codes of Ethics translate broad moral and professional principles into clear, practical guidance for day-to-day professional decision-making. They are intended to be understandable and applicable, unlike abstract ethical philosophy. Codes do not replace legislation, nor are they designed to prevent lawsuits or obtain funding. Their primary purpose is to guide professional conduct and protect the public interest.