Emacs revert-buff (s-u): what is s-u?

The emacs help page for the M-x revert-buffer command says that it开发者_开发知识库 is bound to "s-u". What the heck is s-u? I know M-x is Meta-x (usually alt-x), and I know that C-x is Control-x. But what is s-u?

On Mac OS X 10.6.8 (Snow Leopard) with Emacs: 23.3.1, s-u corresponds to Cmd-u.

The "s-" modifier is the "super" key, which on a standard PC keyboard is the window key.

This makes such shortcuts unusable on Windows AFAIK, but I have a few bound on my Linux.

I don't know what key this corresponds to on an Apple keyboard though.

• What does "s-[keyname]" refer to in Emacs, and how do I tell Emacs to ignore it?
• https://superuser.com/questions/204946/what-is-emacs-keybinding-s-u

Summary: It's your "Super" key.

(Emacs is nothing if not consistent with their naming - apparently it's usually Meta)