| \input texinfo @c -*-texinfo-*-
                     | @c %**start of header
                     | @setfilename appendix.info
                     | 
                     | @ifnottex
                     | @node Top
                     | @top Appendix
                     | @end ifnottex
                     | 
                     | @menu
                     | * Introduction::
                     | * Appendices::
This is wrong: it -->| * Index::
is a subsection, not | @end menu
a chapter.           | 
                     | @node Introduction
                     | @chapter Introduction
                     | 
                     | @node Appendices
This is (i) empty,   | @menu
(ii) between @node   | @end menu
and @appendix!!!     | 
                     | @appendix Appendices
                     | 
                     | @node Index
                     | @appendixsec Index

Thanks!

(This is Emacs 21.3.1's Texinfo.el.)