Such codes exist in most professions to guide interactions between specialists with advanced knowledge, e.g. doctors, lawyers, engineers, stonemasons, and the general public. They are often not part of any more general theory of ethics but accepted as pragmatic necessities.
As the public is in general incapable of distinguishing good from bad decisions, ethical codes are normally part of a profession's own self-regulation. Public guidance typically is confined to ensuring that there is such an internally consistent code, and imposing stricter rules if a profession, e.g. accounting, is deficient in the extreme.
Ethical codes are distinct from moral codes that apply to the education and religion of a whole larger society. Not only are they more specialized, they are more internally consistent, and typically can be applied without a great deal of interpretation by an ordinary practitioner of the speciality.