Historical Rules · 25 August 2017
Rule 206.4
Official source text from the 25 August 2017 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 Tournament Rules). See the Magic Tournament Rules for the current definitions of the constructed formats (WPN.Wizards.com/en/resources/rules-documents).