It seems to be pretty strict, eg.
Example of prohibited advertising:
The Rappido Company is advertising a remote-controlled toy car like one seen in an
animated film. The advertisement is broadcast on Saturday morning on a TV channel for
children during a cartoon program. The ad is in animated film format and shows a young
boy who is thrilled to be operating his high-speed car. This ad would be prohibited.
But there's no mention of product placement. I imagine that would be hard to account for.