Once you have this on screen, to delete the rule, execute “iptables -D” followed by a space, then the chain the rule is on (for instance, input), and the number. If I wanted to delete my 25565 TCP port from above, I would execute “iptables -D INPUT 7”
It needs some cleaning up, but removing a rule is missing from that wiki page.
Yes, the -D in iptables -D is case sensitive, using -d will tell you invalid arguments, as -d is not an option for iptables. As for the INPUT, it is case sensitive to the name of the chain your editing, as you may also use OUTPUT, or FORWARD as chains. Remember, the chain is the category your rules are in, in the image above, ALL of my rules are in INPUT because I don’t have any outbound rules.
Realistically, half the mineos wiki could be cleared out with non-Minecraft things people could find through simple googling, but it’s still a service for them to have a first place to check, to know what to look for and what things are called.