Things that might refer to a tragic accident where Google wouldn't want to put inappropriate ads, "crash" and "driving" next to "accident" and of course, "funeral", "death", "murder", "kill"... it seems to analyze the context of the article. Some might not be affected if it's just a small portion of a big article... while if you put bad words in the first paragraph of a smaller article, it might more easily trigger it.

I'm having a hard time on one of my site with stop words like that where I visit some tragic events in history... you have to find ways to express such things in a more colorful or poetic way, and use less clinical terms.

Gore.

Still haven't decided if that's a stop-word because it's violent or because it's political.

("Gore" generates PSA's in the context of movie reviews on my site. I'm STILL not sure if that's because the mediabot thinks the review is political in nature or violent in nature.)

It also has to with the number of times the stop word is mentioned or how many times it is mentioned in combination with other stop words.

For example, it took a while for the Google bot to turn one of my pages to PSAs after many repeated news headlines that had to with "which characters die" in the fictional book the site covers, and other variations of wordings of that, including "dead" and "death".

The good news about stop words is that if they trigger PSAs when they really shouldn't, like when your article mentions "death" in a context that isn't objectionable, an email to Google explaining the problem will usually get the page turned back on.

Notice G will only do this (or only can do this?) for problems of PSAs due to stop words, not for problems of incorrectly targeted ads due to unfortunate keywords.

I have some NTSB accident reports. Many of them cause PSAs.

NOT adult terms - I have a list of those already

I had the opportunity to test AdSense of one of my clients sites for medical equipment.

The treatment systems was all around the holes used at adult content, but AdSense recognized it as terms in medical context and showed perfect targeted ads for similar medical equipment.