Sadly, I can't post a url to a blog. But on SeRoundTable there is a post about the word "Hostage" preventing YPN ads from showing at their site. There is also a reply from Yahoo suggesting to remove the word to show the ads. Anyway, Yahoo fixed this situation from their side.
By reading the article, it isn't clear enough if it is a feature or a bug.
Is there something similar in Adsense?
It would be great to know so as not to prevent ads from showing inadvertely.
I wish they did. I keep getting untargeted ads on a site just because of two pages elsewhere in the site that are a different topic - totally different target audience, though consistent with the nature of the site. It has to kill clickthroughs on other pages, I might have to remove that little 2 page section from the site altogether. If it's in the global navigation it can turn up anywhere, even if it isn't right for other pages.