Historical Rules · 1 October 2009
Rule 205.4
Official source text from the 1 October 2009 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 (http://www.wizards.com/Magic/TCG/Events.aspx?x=dci/doccenter/home).