In emacs with X, Edit->Copy is mapped to "<copy>" - what key is that on a Linux based PC?

In my Linux setup, Emacs has the Edit->Copy menu item mapped to -- what key is that? And where does it get that keyname definition from? Is that internal to emacs? Or does it get that further upstream?

Specifically, I am running Gnome under Ubuntu Lucid (10.04LTS) - but I believe this is a far more generic question.

Is it, perhaps, that it is mappe开发者_高级运维d to non-existant keys on a standard keyboard? (I recall earlier Sun keyboards having such keys.)

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Yes, it's a standard X11 keysym for which there are no equivalents on a 105-key PC keyboard. Sun and various other workstation keyboards had such keys, and you can find them on some multimedia PC keyboards.