One of a set of explicit or understood regulations or principles governing conduct within a particular activity or sphere.
Example: As mentioned the farm is sells its eggs under the Lion Code, and as a result has to abide by many RULES and regulations. With laying birds many RULES apply, related to the buying in of pullets, hygiene, housekeeping, laying flock monitoring, the environment (e.g. lights, protection against the elements and predators), feed and water, and staff (competence and training).