There are pretty much many strong guidelines that one can follow while online , but I believe that these are pretty celver ones.
If you read the first two optimizations that people use , you will find that google has been researching about people and how they use adsense to garner more money for a long time.
People actually, put ads with their content and are make their content in the same color as the ads and that makes some people think that these are publisher created content.
Also, some guys will put all the ads just below a welcome message like
“todays top picks”
And that is it ,one is led to believe in its originality.
Google conducts regular Webinars all the time to let you know of what all they forbid and what all they really take seriously.
I am always a believer of genuine content though