Rolex Warranty Validation System

[vtsakiris]

When I recently bought my Rolex from my AD he used an iphone with a card reader attached to the bottom to swipe the warranty card and he showed me on the screen the successful transaction of the warranty beeing validated.
Last year when I bought another watch from the same AD he used an iPad and he manually entered the data and again showed me the succesfull transaction.
He told me that the new system is enforced by rolex recently.

My question is what happens when you buy from a grey dealer? Is the watch registered (card swiped) at an AD at a previous time? How you know that the warranty card is actually swiped and the warranty valid? And finally if the card is actually swiped how do you know when, 1 month or one year before this resulting in 5 years minus warranty?