You can set a customer to automatically generate SO Acknowledgment upon saving, this bypasses the need to use this screen and it will appear on the screen after you hit save, you can then use the EMAIL button to send using your local outlook to the customer.
Otherwise, you will use this screen where you can select any of the lines and simply hit the PRINT Selected button, if your customer has an email it will generate and send the acknowledgment using email.
You can also view the SO Ack. using the preview where you can then choose to print or email.
An audit facility is kept on all documents where we store who generated which document, at what time, and how it was delivered to the customer.