Re: Info-scroll-prefer-subnodes default in Emacs.

[Karl Berry]

    One way is to have two kinds of
    menus, one that represents the document's structure and one that
    doesn't.  The index could say `* Index:' instead of `* Menu:'.  It
    would work the same in m but differently in SPC.  Karl, what do you
    think?

That sounds like a very clean idea to me, except ...
that new info files then won't be compatible with old Info readers.
We've gone to great lengths to avoid such incompatibilities in the past.

My idea along these lines was not as elegant, but it retains
compatibility: have makeinfo output a magic cookie (say ^H^[index^H^],
for the sake of argument, similar to the new cookie we use for images)
at the beginning of an index.  New info readers will recognize that, not
display it, and do the right thing.  Old info readers will display it,
which is ugly but not fatal -- the index entries would still work.

    Another way is to do the index using xrefs instead of menus.

Seems more verbose.