Ahh, good point. Okay, here's how I think it should work:

If you have the CVV field enabled, it will be sent during the initial payment, but it won't be saved and it won't be sent on any subsequent charges using that same credit card. You can set up the gateway to reject the transaction if the CVV does not match the correct value, but not to require the CVV. That way it will be verified on the first transaction, but not required later.

If you don't have the CVV field enabled, it's obviously never sent and never stored. You just have to make sure to set up the gateway to not require it.

What do you think?