unadvertisement

noun2

1. •
   A public notice that warns of the risks associated with a product, rather than promoting it like an advertisement.

   • We created some “unadvertisements.” This one, for example, says, “Mrs. R is doing fine without vasodilators,” and it goes on to explain some of the physiology of her condition, […] — 1983
2. •
   The withdrawal of an earlier notification.