youtube keyboard shortcuts window

[pleasejust]

Hi. Every once in a while, while I'm watching a youtube video, I'll see a large window appear that shows a list of keyboard shortcuts for youtube. At the top left it just says Keyboard Shortcuts. They're all related to youtube. At the bottom right it says dismiss, I click on it and it goes away. For the life of me I can't figure out what key combination I pressed to make it appear. I'm pressing everything, checking setting but it's not showing up. I can't even find on google how to make it appear. Wtf? Weird, man. Thanks anyhow.

[pleasejust]

figured it out....... SHIFT+?