Routing Tables and FW Marks for AXT1800

I can see in the openwrt firewall rules that there are standard lookup routing tables configured for different rule sets (bypass vpn, dns, etc.). Those rules apply for certain fw marks ( 0x60000, 0x80000).
But i cant find where those marks are set in the first place, iptables / firewall rules.

Where can i find the rules to set those marks?

set the iptables/firewall rules, can reference as: