Which runs first in mangle: custom chain or prerouting chain

RouterOS General
1

I’m currently doing load balancing with Nth method for my final project in college and I’m following steps on this page:

https://wiki.mikrotik.com/wiki/NTH_load_balancing_with_masquerade_(another_approach)

There are 2 parts that I dont understand from the page.

  1. In “Packet Route Logic” part (the “New packet from unseen addresses” point), it says that new packet comes to section C first. Why not to section A first? Doesnt routeros read the rule from the top to bottom? Is there any priority to run the chain? (like prerouting chain processed first then the custom chain). Or is the explanation gone wrong?
  2. In address list command explanation, it explains that I can use in interface if I have one incoming LAN, can you give me the example of the command?

I hope someone could answer this asap. Ive been looking thru so many references but I still cant get it yet my deadline is getting closer…

Thankyou!!!