This must have been covered before. I don't know if this has been added to FAQ either. Please forgive me for the ignorance. But I happened to find the Fn+Shift+R function in Bash. It's quite helpful for looking up old command line input. For the sake of completeness, I put all the ones I know here.
Fn+Shift+R = reverse-i-search in Bash
(type in string to search, hit Fn+Shift+R again to scroll backwards, i.e. find an earlier matching result)
Fn+Shift+C = screen shots
Fn+Shift+/? = `
Fn+Shift+space = \
Fn+Shift+'" = ^
Fn+Shift+.:= {
Fn+Shift+returen = }
Fn+Shift+backspace = [
Fn+Shift+,; = ]
