I remember Google also had something similar a long time back on <i>Google Webmasters</i> (apparently now integrated under <i>Google Search Central</i> - <a href="https://developers.google.com/search" rel="nofollow">https://developers.google.com/search</a> ) with <i>SiteMaps</i> - <a href="https://developers.google.com/search/docs/advanced/sitemaps/overview" rel="nofollow">https://developers.google.com/search/docs/advanced/sitemaps/...</a> . But it required a Google account. Glad to see the beginning of a standard emerging that anyone can use. Pity that Google is ignoring it though.