Historical Rules · 5 October 2018
Rule 206.4
Official source text from the 5 October 2018 Rules release
Players may include cards from any printing in their constructed decks if those cards appear in sets allowed in that format (or those cards are specifically allowed by the Magic: The Gathering Tournament Rules). See the Magic: The Gathering Tournament Rules for the current definitions of the constructed formats (WPN.Wizards.com/en/resources/rules-documents).