What is NAP? Where is it used and what are the rules

NAP is a non aggression policy or no attack pact or similar. This is just an agreement between alliances in a state not to attack each other. There are no set rules but the alliances will agree among themselves.

Typically it can mean the top 10 / 15 or more alliances agreeing not to attack each other. But alliance leaders in each state decide who should be included.