Concatenating these two parts reproduces the original file name.
On most systems, the directory part is everything up to and including
-the last slash; the nondirectory part is the rest. The rules in VMS
-syntax are complicated.
+the last slash (or backslash, on MS-DOS or MS-Windows); the nondirectory
+part is the rest. The rules in VMS syntax are complicated.
For some purposes, the nondirectory part is further subdivided into
the name proper and the @dfn{version number}. On most systems, only
@end example
@end defun
+@defvar directory-sep-char
+@tindex directory-sep-char
+This variable holds the character that the system normally uses to
+separate file name components. The value is @code{?/} on GNU and Unix
+systems, and @code{?\\} on MS-DOS and MS-Windows. Note that file names
+using slashes as separators work properly in Emacs on all of these
+systems; you are not obliged to use backslashes on Microsoft systems.
+@end defvar
+
@node Directory Names
@comment node-name, next, previous, up
@subsection Directory Names