You're trying to troll, but this post is for everyone else you dona good job of baiting.
Without knowing details, two possibilies.
Norms are the word they use, interchangeable with habits, practices or expectations. It'd be silly and laborious to write a rule for how kids sit in a desk ("feet on the floor, not tapping pencil, head up, etc.) and every other behavior in school. Enforcing it, because it is a rule, would be exhausting. But expressing the expectations as a habit, classroom practice, or norm communicates the expectation to students, allows the pragmatism that you don't get with rules, and serves to improve the acadamic behaviors in the building. Put another way, if you make a rule for not titling/naming/dating your work, you need clear consequence. Coming up with, communicating, and then enforcing those consequences for every behavior is not efficient or effective. Norms (or habits, practices, expectations) are the more effiecient way to manage these behaviors.
If the norms you observe take the place of bigger "rules" like fighting, the norms may just be an efficient way to communicate the rule. Refer to your son's code of conduct to see if "rules" as you envision them, still exist. Otherwise, the norms may be what get posted on placards and parent letters, insead of the technical language and nuance found in the code of conduct.