<http://schema.org/description>
"I spotted an interesting discussion, asking if Google's AdWords bot, aka AdBot, supports the canonical tag.  The canonical tag was launched in 2009 and has been used by many developers since then.  Bu"^^<http://www.w3.org/2001/XMLSchema#string>
<https://www.seroundtable.com/adbot-google-canonical-support-13617.html>