Meaning this bit was added to the spec:

   The name of the XML file is significant. Each XML file can only
   declare actions from the namespace of it's own name; for example
   actions org.foobar.action-a, org.foobar.action-b and
   org.foobar.action-c would all go into the file org.foobar.policy
   while actions com.my-company.product-awesome.action-a,
   com.mycompany.product-awesome.action-b would go into the file
   com.mycompany.product-awesome.policy.

This is the output of the validator on a broken .policy file

  $ polkit-policy-file-validate /usr/share/PolicyKit/policy/gnome-clock-applet-mechanism.policy
  WARNING: The action org.gnome.clockapplet.mechanism.configurehwclock does not
           belong in a policy file named gnome-clock-applet-mechanism.policy.
           A future version of PolicyKit will ignore this action.

  WARNING: The action org.gnome.clockapplet.mechanism.settime does not
           belong in a policy file named gnome-clock-applet-mechanism.policy.
           A future version of PolicyKit will ignore this action.

  WARNING: The action org.gnome.clockapplet.mechanism.settimezone does not
           belong in a policy file named gnome-clock-applet-mechanism.policy.
           A future version of PolicyKit will ignore this action.

  ERROR: /usr/share/PolicyKit/policy/gnome-clock-applet-mechanism.policy did not validate

We currently don't enforce this but will in a future version. The
rationale is that we can avoid loading all .policy files at startup
which would be a performance win.