Doc updates for default values of some -function vars no longer being nil

* doc/emacs/files.texi (Backup Names):
* doc/emacs/arevert-xtra.texi (Supporting additional buffers):
* doc/lispref/backups.texi (Making Backups, Reverting):
Update for default values of some -function vars no longer being nil.

* etc/NEWS: Related edits.

1 files changed, 3 insertions, 3 deletions

diff --git a/doc/emacs/arevert-xtra.texi b/doc/emacs/arevert-xtra.texi
index a13f59b69b..0f05d1db0e 100644
--- a/doc/emacs/arevert-xtra.texi
+++ b/doc/emacs/arevert-xtra.texi
@@ -103,11 +103,11 @@ arguments to list only some of the files.  @file{*Find*} and
 This section is intended for Elisp programmers who would like to add
 support for auto-reverting new types of buffers.
 
-To support auto-reverting the buffer must first of all have a
+To support auto-reverting the buffer must first of all have a suitable
 @code{revert-buffer-function}.  @xref{Definition of
 revert-buffer-function,, Reverting, elisp, the Emacs Lisp Reference Manual}.
 
-In addition, it @emph{must} have a @code{buffer-stale-function}.
+In addition, it must have a @code{buffer-stale-function}.
 
 @c FIXME only defvar in all of doc/emacs!
 @defvar buffer-stale-function
@@ -149,7 +149,7 @@ also be useful if the function is consulted for purposes other than
 auto-reverting.
 @end defvar
 
-Once the buffer has a @code{revert-buffer-function} and a
+Once the buffer has a suitable @code{revert-buffer-function} and
 @code{buffer-stale-function}, several problems usually remain.
 
 The buffer will only auto-revert if it is marked unmodified.  Hence,