Improve documentation of 'w32-scroll-lock-modifier'

* doc/emacs/msdos.texi (Windows Keyboard): Document how to set up
w32-scroll-lock-modifier so that Scroll Lock toggles the LED.

* src/w32fns.c (syms_of_w32fns) <w32-scroll-lock-modifier>: Doc
fix.  (Bug#25204)

1 files changed, 5 insertions, 1 deletions

diff --git a/doc/emacs/msdos.texi b/doc/emacs/msdos.texi
index 47ba23b95aa..d0e9ab45c25 100644
--- a/doc/emacs/msdos.texi
+++ b/doc/emacs/msdos.texi
@@ -580,7 +580,11 @@ variable @code{w32-rwindow-modifier} controls the effect of the right
 Windows key, and @code{w32-scroll-lock-modifier} does the same for the
 @key{ScrLock} key.  If these variables are set to @code{nil}, the
 right Windows key produces the symbol @code{rwindow} and @key{ScrLock}
-produces the symbol @code{scroll}.
+produces the symbol @code{scroll}.  If you want @key{ScrLock} to
+produce the same effect as in other applications, i.e.@: toggle the
+Scroll Lock @acronym{LED} indication on the keyboard, set
+@code{w32-scroll-lock-modifier} to @code{t} or any non-@code{nil}
+value other than the above modifier symbols.
 
 @vindex w32-pass-alt-to-system
 @cindex Windows system menu