Once again about anacron cron cron.daily

[Harry Putnam <reader@newsguy.com>]

I'm still not getting the whole picture of what is supposed to happen
on a machine with both anacron and cron installed.

I understand the reasoning for machines that are not up all the time,
where anacron picks up the slack for cron jobs that came up with
the machine down.

I get that.

But in my case and I'm kind of guessing it is the general case.

I have lines like the one below in /etc/crontab 

[...] test -x /usr/sbin/anacron || ( cd / && run-parts --report 
                                               /etc/cron.daily )

Ok, it tests for the presence of /usr/sbin/anacron, checks that it is
executable and sees to it that this user has permission to run it.

But where and when does anacron actually get called to run?

That line appears to expect anacron to be called somewhere else.
So is anacron supposed to be started at some run level?

In my case it is not listed in any run levels.

A hasty read of 'man update-rc.d' appears to indicate it is incapable
of the most basic job... simply showing the run levels and what is
running on them.

Maybe there is some better tool, but using rcconf I see that anacron
has not been set to run .. no asterisk in box.

I've never taken any actions on anacron and don't remember even
installing it purposely... so am I supposed to put it into a run
level?

Or, does it get called somewhere else in the cron setup?