If an XML developer sends  the CVV2 in the xml message, BookingCenter will use it to transact the deposit. However, it would be advantageous only if a Site were using MyCard (Payment Gateway product) to actually process a deposit at time of booking. If not, then asking for - and sending - the CVV2  it is not a good idea , as it only creates a security liability with no benefit.

It is up to the XML to enforce collecting the CVV2 at the UI level, as BookingCenter's use of 'require CVV2' can not be enforced when an XML developer is developing the UI for the booking process.