Historical Rules · 1 February 2014
Rule 312.6
Official source text from the 1 February 2014 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.)