Basic blender went bad (motor ran but spindle wasn’t rotating). I wanted to disassemble to see if it could be repaired. Three of the four screws were Phillips head. I had to cut the casing open in order to discover why I couldn’t unscrew the fourth. It was a slotted spanner.
It’s called an “H-type” head. I found some tools for that on eBay but was reluctant to spend any money on something I’d probably never need again, ever. But this video shows a hack using scissors.
https://www.youtube.com/watch?v=GA6_S9YkZEc
I didn’t have a pair laying around that worked but the video inspired me to MacGyver my way to remove that aberration against all that’s good in humanity.