Texinfo 4.0 - Node Line Requirements

Here are several requirements for @node lines:

All the node names for a single Info file must be unique. Duplicates confuse the Info movement commands. This means, for example, that if you end every chapter with a summary, you must name each summary node differently. You cannot just call each one "Summary". You may, however, duplicate the titles of chapters, sections, and the like. Thus you can end each chapter in a book with a section called "Summary", so long as the node names for those sections are all different.
A pointer name must be the name of a node. The node to which a pointer points may come before or after the node containing the pointer.
@-commands used in node names generally confuse Info, so you should avoid them. For a few rare cases when this is useful, Texinfo has limited support for using @-commands in node names; see section Pointer Validation. Thus, the beginning of the section called @chapter looks like this:
```
@node  chapter, unnumbered & appendix, makeinfo top, Structuring
@comment  node-name,  next,  previous,  up
@section @code{@@chapter}
@findex chapter
```
Unfortunately, you cannot use periods, commas, colons or apostrophes within a node name; these confuse TeX or the Info formatters. For example, the following is a section title:
```
@code{@@unnumberedsec}, @code{@@appendixsec}, @code{@@heading}
```
The corresponding node name is:
```
unnumberedsec appendixsec heading
```
Case is significant.