Modexplainations ingame
I suggest to add a link in the motd of every public room which links to a closed thread on the forum in which the respective mod is explained in a few short sentences plus a few tipps for this mod aswell.
I see a lot of players enter rooms who ask things like "what is this mod?","what are the rules here?" or "how is this mod different from abd"? etc.
Ofcourse you can say they just have to check the gamerules but ,tbh, the information given in the gamerules for noobs is lackluster at best since most noobs dont know which gamerules are the important ones they have to look at to get an idea of the mod and even if they do they dont know the difference in those rules to the mods they know already.
Another pro of this would be to guide new players to the forum where they maybe discover new things they might like.
I am honestly baffled this was not added many,many years ago btw.