Historical Rules · 1 October 2009
Rule 112.10
Official source text from the 1 October 2009 Rules release
Effects can add or remove abilities of objects. An effect that adds an ability will state that the object "gains" or "has" that ability. An effect that removes an ability will state that the object "loses" that ability. Effects that remove an ability remove all instances of it. If two or more effects add and remove the same ability, in general the most recent one prevails. (See rule 613, "Interaction of Continuous Effects.")