+@defvar buffer-saved-size
+The value of this buffer-local variable is the length of the current
+buffer, when it was last read in, saved, or auto-saved. This is
+used to detect a substantial decrease in size, and turn off auto-saving
+in response.
+
+If it is @minus{}1, that means auto-saving is temporarily shut off in
+this buffer due to a substantial decrease in size. Explicitly saving
+the buffer stores a positive value in this variable, thus reenabling
+auto-saving. Turning auto-save mode off or on also updates this
+variable, so that the substantial decrease in size is forgotten.
+@end defvar
+
+@defvar auto-save-list-file-name
+This variable (if non-@code{nil}) specifies a file for recording the
+names of all the auto-save files. Each time Emacs does auto-saving, it
+writes two lines into this file for each buffer that has auto-saving
+enabled. The first line gives the name of the visited file (it's empty
+if the buffer has none), and the second gives the name of the auto-save
+file.
+
+When Emacs exits normally, it deletes this file; if Emacs crashes, you
+can look in the file to find all the auto-save files that might contain
+work that was otherwise lost. The @code{recover-session} command uses
+this file to find them.
+
+The default name for this file specifies your home directory and starts
+with @samp{.saves-}. It also contains the Emacs process @sc{id} and the
+host name.
+@end defvar
+
+@defvar auto-save-list-file-prefix
+@tindex auto-save-list-file-prefix
+After Emacs reads your init file, it initializes
+@code{auto-save-list-file-name} (if you have not already set it
+non-@code{nil}) based on this prefix, adding the host name and process
+ID. If you set this to @code{nil} in your init file, then Emacs does
+not initialize @code{auto-save-list-file-name}.
+@end defvar
+
+@node Reverting