I have recently started playing and have purchased almost all of the product out there for the game. I have cards with secrecy on them but I cannot find it in the rules reference. Please help.

It's not in the main rulebook, but it should be printed in any expansion that has any secrecy cards. Secrecy X means if your threat is 20 or less, you reduce the cost to play the card by X. So a card with 3 cost and secrecy 2 would only cost 1 if your threat is 20 or less.

Thank you for the information