According to Snoredog, the card only holds the last seven days of use with up to three sessions each day. It holds six months of compliance data to date. To label a Smartcard, write on the white stripe at the bottom of the card. Normally, Encore Pro erases the data from the Smartcard when it reads it. Rested Gal has discussed this issue and gives ways of preventing the data from being erased. If you accidentally press erase at the end of the read sequence, you will obliterate all past data on the card.