martin56

It's a whitelist for parked domains...

That's right, you didn't say that. You said there is a "public" and a "private" list. To me this sounds like the "private" one is somehow hidden from the public and cannot be seen which isn't the case.

No, there is no private list. See https://news.ycombinator.com/item?id=8104070

No, there is no private list, it's just the public one. You can check out the key header whitelist here: http://cheme.com/ Visit this site with "Acceptable Ads" enabled and disabled and you will see the difference. Notice the "data-adblockkey" in the source. This was publically announced in their "Acceptable Ads proposal" forum here and later added to the public list: https://adblockplus.org/forum/viewtopic.php?f=12&t=17699