Wait a second
I have to read things closer. Really, the description of LN has a personal code in it!? It uses the that "or" connector too. So I'm not sure a personal code of honor is the most helpful part of societal cohesion, but its right there in the description of lawfulness.A lawful neutral character acts as law, tradition, or a personal code directs her.
Still, reading the whole SRD clearly indicates that there is more than just a "pick your code" that this quote might indicate. A lawful character from the description of lawfulness, wants societal order and generally respects authority.