Historical Rules · 30 September 2011
Rule 311.6
Official source text from the 30 September 2011 Rules release
If a non-ongoing scheme card is face up in the command zone, and it isn't the source of a triggered ability that has triggered but not yet left the stack, that scheme card is turned face down and put on the bottom of its owner's scheme deck the next time a player would receive priority. (This is a state-based action. See rule 704.)