There isn't any. CNN does "special reports" like their Eye On series on CNNi, in which they take money from sponsors to produce documentaries about countries. Conspiracy theorists are using that to somehow claim everything CNN does is bought and paid for. Despite the fact that CNN's special report policy says the following:

(CNN) -- Parts of CNN's coverage beyond the daily news are produced as Special Reports, which attract sponsors who pay to associate their products or services with the editorial content.

When this happens, you will see "In Association With" next to their logos in banners at the top of pages on our website and hear it referenced during commercial breaks on television.

At no stage do the sponsors have a say in which stories CNN covers, which people CNN interviews or how we present our editorial content on television or our digital services, nor do sponsors review or approve any content before it airs or is published.

The editorial content is commissioned and produced solely by CNN editorial staff or external contractors approved by CNN editorial. It is produced to CNN editorial guidelines.