Liz - PrtScn is short for Parrot Scan. It is a legacy from the early days of computing before they invented computer viruses. At that time, the malicious attackers released large highly coloured birds into the warehouse sized rooms holding the wardrobe sized computer processing units. Shed feathers caused havoc by jamming the computer tape drives and sometimes the birds attacked the hamsters running round in the power backup wheels.
They tried to combat all this by including a button which, if pressed, will scan the room for parrots, and hopefully prevent you getting the Norwegian Blue Screen of Death.

I suspect that Little Hawk's problem with lost postings is probably due to Mudcat's computer incorrectly identifying him as a parrot.

Quack!
Geoff the Duck.