The savegame folder, the 10-minute autosave, why characters never move (Keen stores them client-side), the four-step transfer, what goes wrong, and the backup to take before and after.
One .sav file and a rule about its name: the Windows save path, the server’s Savegames folder, why you must not rename the file, and why world rules travel in the save rather than the INI.
Two files and a name: where the .db and .fwl live on every platform, where to put them on the server, the password rule that blocks the start, and why characters come along for free.