The form was actually perpetuated by the industry even though it has not been a requirement for 16 years. On line applications have never required the form and over a year ago the CAA produced a IN announcing the removal of the form. The IN was never published, possibly because the CAA did not want to admit that it had never been an EASA or even a JAA requirement; they simply removed the form and hopefully, it is now dead and gone. I received confirmation of this a few days ago.
It was originally used because the QXC was conducted after all PPL training and Skill tests had been completed, and was the final qualifying event that was otherwise unchecked, hence a certificate.