I have a question;

In last nights episode Carmella was talking to Tony about finances,etc and Tony said to her something Like the less she knew the better. Then he said as soon as he had the "numbers" for the bills he'd give her the info (or something like that). I know he means the serial numbers for the bills, but can someone explain to me further what he's talking about? What bills? Not having any experience in counterfeiting, I am kind of confused.
TIS