Can I have a repository in another repository's ignored directory?

[Chris Green]

This may sound like rather an odd idea but bear with me.

I have a mercurial repository that I synchronise (using syncthing)
across several systems.  This works beautifully, I can use mercurial
to manage the files on any of the several systems and it works just as
one would hope. (there's only me using the system).

I'd like to have another, independent, repository available on all
these systems and I'd prefer not to add yet another synchronised
directory. 

So, can I add a directory to the existing repository, call it say
'dirabc' and add it to the .hgignore of the parent repository so it is
ignored and then create a new mercurial repository in 'dirabc'?

I can't see anything wrong with doing this, am I missing anything?

-- 
Chris Green