bug#52126: Problematic characters in info node names

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Mon, 29 Nov 2021 09:44:17 -0800
> Cc: 52126@debbugs.gnu.org, Protesilaos Stavrou <info@protesilaos.com>,
>  Kyle Meyer <kyle@kyleam.com>, Glenn Morris <rgm@gnu.org>
> 
> I read in (info "(texinfo) Node Line Requirements") that:
> 
>    * Unfortunately, you cannot reliably use periods, commas, or colons
>      within a node name; these can confuse the Info reader.  Also, a
>      node name may not start with a left parenthesis preceding a right
>      parenthesis, as in '(not)allowed', since this syntax is used to
>      specify an external manual.  (Perhaps these limitations will be
>      removed some day.)

This is mainly because of the stand-alone Info reader.  The Emacs Info
mode copes with these characters in node names much better.

So yes, it is desirable to avoid them, but it isn't a catastrophe if
they are there.