The implementation of principles is generally achieved through the development of practices, which generally address issues of importance for a specific commodity and/or production system. Better Management Practices (BMP), Good Aquaculture Practices (GAP), Better Aquaculture Practices (BAP) and others are all examples of practices for the implementation of the principles. BMP, GAP and their counterparts are somehow "indicative", as opposed to standards, either mandatory (e.g. legal documents) or voluntary, which are more "normative" rules for a product or process.