Re: Info bug with @xref{Sample .emacs File, , , ccmode, the CC Mode Manual}.

[Richard M. Stallman]

    And, so far as I know, we've _NEVER_ had any problems with it.  It has
    simply worked.  More to the point, makeinfo has never given a warning
    about it.

There are situations in which it would not work.
Specifically, if you try to follow a menu item like this,

  * Init Example: Sample .emacs File.

Info would look for a node called `Sample '.

There is no way to detect that there is a problem with that
menu item (except that it will probably fail to find that
node), so we decided to put in a warning for using a node
name that is susceptible to the problem.