How do "Call for Articles" orders work?

[migwrinomo]

I see a lot of orders under the Call for Articles category. I'm assuming the client puts out a call and hopes to get a variety of articles on the topics requested, then pics which ones he/she likes and pays for them.

If you submit an article to one of these orders and it is not selected by the client, are you notified?

I am curious how well this order type works for a client wanting multiple articles on different topics. I would think there would be a problem with getting multiple articles on one topic and no articles on other topics since there is no communication between the writers and the client.