The about and mentions markups are properties of webpage schema which explicitly inform search engines like Google and Bing what matters a page is mainly about and what other subject areas are just currently being talked about or referred to. It incorporates references for the Schema.org and Google documentation for https://bookmarkzap.com/story19317253/the-rich-snippets-autom%C3%A1ticos-json-ld-opengraph-seo-diaries