<http://schema.org/description>
"I am not sure when this happened, but in the past when you did a search in Yahoo and a site with an RSS showed in the results, an \"Add To My Yahoo!\" link was present.  The \"Add To My Yahoo!\" link was "^^<http://www.w3.org/2001/XMLSchema#string>
<https://www.seroundtable.com/archives/003869.html>