Where user groups came from, the five flags, Keen’s Admin/Friend/Guest examples, reserved slots, the retired top-level password key, and why a fresh server ships closed with randomised passwords.
Where the Player ID is, what putting it in Owner ID unlocks, what an admin can and cannot do, why there is no whitelist, and the community disagreement over Player ID versus EOS ID.
How to make yourself admin, the kick and ban commands that work on a vanilla server, the 1.0 ID change that broke admin lists, and why devcommands is refused on a dedicated server — with the three real workarounds.
World modifiers are launch arguments on a dedicated server, not a menu. Every preset, modifier and key with its exact spelling, the ordering rule that silently undoes your changes, and how to change the rules on a world you already play.