I keep forgetting how each of the following CSS values rolls back a declaration to a different point in the cascade. It was about time I jotted it down for my future self before it slips my mind again for the 1000th time.
initial- Applies the default value as listed in the CSS spec
unset- Inherits or falls back to spec default value
revert- Reverts to the user agent's default value
revert-layer- Rolls back to the value in a previous cascade layer