Ever wondered what the SysRq key does? Turns out it’s a kind of convoluted programmable key that hardcore programmers can commandeer. From the sounds of it’s it’s just as “programmable” and useful as the old function keys were on the Commodore 64 and Vic-20… eg not very much at all.

There’s also a less geeky explanation from the Straight Dope people, which goes through some of the other lesser-used keys too, including the mysterious Scroll Lock, which does have a modern use, at least in Excel, and Break, which when pressed with Ctrl will amongst other things stop execution in the VB IDE or batch files in DOS the command prompt.

Me, I wish the Insert key could be abolished. I don’t think I know of a more annoying toggle.