Historical Rules · 11 November 2016
Rule 702.16d
Official source text from the 11 November 2016 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.”)