It means that it only checks per object permission.
You can see a recent proposal I made on Django forum that's related to that topic:
I don't use django-rules-light anymore, I prefer to implement an AuthBackend as described in the above post.
For securing querysets (filtering out results that a user can't see), I do that at the controller level (the Router class that sits in-between a model and its set of views) in CRUDLFA+.
Good luck