On Fri, Nov 22, 2019 at 10:16 AM Eli Zaretskii <eliz@gnu.org> wrote:

> The former, with a comment about the (evidently unknown) source of the
> Scroll_Lock "function key".

AFAICS, the X Window System Protocol (
https://www.x.org/releases/X11R7.6/doc/xproto/x11protocol.html) defines the
keysyms as numeric codes with a conventional name, in this case

#xFF14   SCROLL LOCK

which is represented in /usr/include/X11/keysymdef.h as

#define XK_Scroll_Lock                   0xff14

but I don't know how that is converted into a keyboard event.