Historical Rules · 27 September 2013
Rule 702.16a
Official source text from the 27 September 2013 Rules release
Protection is a static ability, written "Protection from [quality]." This quality is usually a color (as in "protection from black") but can be any characteristic value. If the quality happens to be a card name, it is treated as such only if the protection ability specifies that the quality is a name. If the quality is a card type, subtype, or supertype, the ability applies to sources that are permanents with that card type, subtype, or supertype and to any sources not on the battlefield that are of that card type, subtype, or supertype. This is an exception to rule 109.2.