I booked online and received an email with a code number (D1212) which I thought I would have to enter into some machine at some point. However this didn't happen. When I arrived at the Short Stay car park the machine at the barrier issued me with a ticket, which I held onto until we had returned from our holiday. However I found that I didn't know what I was supposed to do when I returned to the car. The Pay machines didn't seem relevant as they didn't have any kind of keyboard to enter the D1212 code. What I had to do was go to the Customer Service kiosk in the car park to ask for instructions, and I was told that I just need to to enter the ticket into the machine, and then enter it again when I was exiting the car park. I feel it would have made more sense to advise me exactly what I would have to do in the email, but the email was not helpful at all, in fact I'd go so far as to say it was totally misleading. This was the only time that I have ever used the Short Stay car park at the airport, and I was left feeling confused from arriving until leaving which doesn't seem right. Furthermore there was no contact details within the email. Overall I would say that some effort should be made to communicate with customers in a way which leaves them knowing exactly what they should expect from arriving to departure from the car park.