Marius Gedminas says:
October 15, 2009 at 10:15 am

Ctrl + Shift + X launches the X Terminal app.

There’s a Ctrl + Shift + I in the web browser that enables reflow mode (zoom in and the paragraphs are reflown to fit within the screen width).

These are documented: Backspace in the browser goes back a page, Space scrolls down a page, Shift + Space scrolls up a page.