A log is kept of all credit/debit card processing done through WorldPay for audit purposes. This screen shows a log of the messages received from WorldPay which are known as callback messages.
Each callback message received is given a unique ID, and is parsed to extract useful information. A Transaction ID and Cart ID are recorded alongside several other parameters.
The Cart ID is comprised of the unique licence request reference, the system short name "SLM", and the customer's unique customer reference, with each of the values separated by a "/".
The actual message text is also retained in its raw format.