<http://schema.org/description>
"Currently, it seems as if Google AdWord's contextual relevancy matching systems are offline.  All (most) AdSense publishers are displaying PSAs or also known as Public Service Ads.  These PSAs show wh"^^<http://www.w3.org/2001/XMLSchema#string>
<https://www.seroundtable.com/archives/000769.html>