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 mapped to non-existant keys on a standard keyboard? (I recall earlier Sun keyboards having such keys.)
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.