Historical Rules · 23 January 2015
Rule 702.16d
Official source text from the 23 January 2015 Rules release
A permanent with protection can’t be equipped by Equipment that have the stated quality or fortified by Fortifications that have the stated quality. Such Equipment or Fortifications become unattached from that permanent as a state-based action, but remain on the battlefield. (See rule 704, “State-Based Actions.”)