section Web Shop
  description   Messages mainly used for interaction with the Web-Shop.
  message customer-agrees The customer agrees with the order (and amount)
  message customer-rejects The customer is not satisfied with the amount and aborts the order
  message choose-method The customer needs to choose a payment method.
  message chooses-cash The customer chooses to pay with cash.
  message chooses-terminal The customer chooses the electronic payment terminal.
  message change+bill The customer receives change and the bill
  message send-invoice The invoice is send to the customer
  message ship-goods The goods are being shipped to the customer
  protocol Human Used to describe human readable messages.