When on, only holding the middle mouse button rotates the camera — left-click drag won't. Leave off to rotate by holding left-click and dragging.
Prints your kill count to the chatbox every time you kill a boss.
Hold Shift and left-click an item in your pack to drop it instantly.
Shift-dropping a stack worth at least this much (store price) asks for confirmation first, so you don't drop good stuff by accident. Set 0 to never warn.
When off, roofs and floors above you hide automatically while you're inside a building.
Turns off all dynamic shadows. The biggest single framerate win on slower machines.
Shift + right-click a tile to mark it (optionally give it a name). Markers are saved on this device. The color sets new markers.
Outlines your real server position, ignoring movement smoothing.
Outlines the tile your character is standing on.
Keybinds
Click a key, then press the key you want (or Esc to clear). Opens the matching panel tab, old-school style. Saved on this device.