The canonical Meta Extension is practically a link element, which defines what the original URL of a document is.
The result displays in search engines as well as on printed pages.
It's mostly used if you have a mobile-version of your page on a subdomain like
https://m.jomenetwork.de and a desktop version like
Search engines will only index the defined URL and not the mobile-page if a canonical link is set.
To avoid problems that could appear when indexing your page, you should always set a canonical link in the
<head>-section of your documents.
<link rel="canonical" href="https://faq.jokenetwork.de">
In the WHATWG WikiUp to date: v2.3.5