What Is Meant by a Code of Practice?

is a way to state clearly your organization's position on important subjects like equality, ethics, contracts, conflict of interest and duty of care. 

for example : 

Ethics

We always conduct our own services honestly and honourably, and expect our clients and suppliers to do the same. Our advice, strategic assistance and the methods imparted through our training, take proper account of ethical considerations, together with the protection and enhancement of the moral position of our clients and suppliers.

Codes of practice are written rules and guidelines issued by an official body or a professional association to its members to help them comply with its ethical standards. People bound by certain codes of practice must act according to these rules so as to avoid a legal process.