@end example
@end defun
+@defvar search-whitespace-regexp
+If this variable is non-@code{nil}, it should be a regular expression
+that says how to search for whitespace. In that case, any group of
+spaces within in a regular expression being searched for stands for
+use of this regular expression. However, spaces inside of constructs
+such as @samp{[@dots{}]} and @samp{*}, @samp{+}, @samp{?} are not
+affected by @code{search-whitespace-regexp}.
+@end defvar
+
@node POSIX Regexps
@section POSIX Regular Expression Searching