We have taken care of this issue for now and warned the player, If it happens again please let us know so that we can resolve the issue. Thanks
A lot of players dont know about the Endgame list, this is why a way to see them or block them being sold is needed.
99% of the people playing minecraft would just see that they want people to sign up on the forums (i.e. extra work) before even getting to log onto the server and just say nope, its not like there's a shortage of MC servers out there.
More like make them run through a little scenario where they have to enter the right answer, and the only commands they can do are to read the rules or supply an answer until they get it all done. About five simple questions which are easily answered if you actually read the question would work: Is it okay to sell a block of stabilized unstable ingots on the market? Is it okay to grab items from an unclaimed house? Should you report if somebody is killing people even though PVP is off? Can you take the time to think through what you just typed and ensure it won't be harmful for young children to read? Is it safe for the server resources to have pipes, ducts, or conduits going in loops? Heck, you could probably do a GUI for it. Once a person hits the /acceptrules command, the gui could pop up to ensure that they read the rules.
If people are ignorant of the rules because they didnt bother to read them and get punished for it, thats their problem not MyMs problem. In the real world people wont coddle you and hold your hand to make sure you don't do anything wrong.