<http://schema.org/description>
"In July, Google officially announced favicons within AdSense ads.  So the ad units will show off the site's favicon, if available, which should increase one's click through rate.But in September, when"^^<http://www.w3.org/2001/XMLSchema#string>
<https://www.seroundtable.com/google-adsense-favicons-missing-17523.html>