708.2b
A face-down permanent can’t be turned face-down. If a spell or ability attempts to turn a face-down permanent face down, nothing happens and that effect doesn’t change any of its characteristics or their copiable values.
A face-down permanent can’t be turned face-down. If a spell or ability attempts to turn a face-down permanent face down, nothing happens and that effect doesn’t change any of its characteristics or their copiable values.