Say why text-quoting-style is not a user option

* doc/lispref/help.texi (Keys in Documentation):
* etc/NEWS: Document why text-quoting-style is not a
customizable variable (Bug#23372).

1 files changed, 4 insertions, 0 deletions

diff --git a/doc/lispref/help.texi b/doc/lispref/help.texi
index 0b8182c521a..58a11f29a4c 100644
--- a/doc/lispref/help.texi
+++ b/doc/lispref/help.texi
@@ -362,6 +362,10 @@ this'} with grave accent and apostrophe, the standard style
 before Emacs version 25.  The default value @code{nil}
 acts like @code{curve} if curved single quotes are displayable, and
 like @code{grave} otherwise.
+
+This variable can be used by experts on platforms that have problems
+with curved quotes.  As it is not intended for casual use, it is not a
+user option.
 @end defvar
 
 @defun substitute-command-keys string