REDU format ruling
A Cat of Ill Omen

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)FLIP: Choose 1 Trap from your Deck and place it on top of your Deck, or, if "Necrovalley" is on the field, you can add that Trap to your hand instead.
Rulings
FLIP: Select 1 Trap Card from your Deck and place it on top of your Deck. If Necrovalley is on the field, you can add the selected Trap Card to your hand instead.
- Show the card to your opponent.
- If Imperial Order & Necrovalley are both active, and A Cat of Ill Omen is flipped, you add the card to your hand because Necrovalley is face-up on the field, even though its effect is negated.
- You select the card for this effect when the effect resolves, not when it activates.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.