Historical Rules · 8 July 2017
Rule 712.2
Official source text from the 8 July 2017 Rules release
One card in each meld pair has an ability that exiles both that object and its counterpart and melds them. To meld the two cards in a meld pair, put them onto the battlefield with their back faces up and combined (see rule 701.35, “Meld”). The resulting permanent is a single object represented by two cards.