MetaExtension canonical
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 https://jokenetwork.de.
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.
Usage
<link rel="canonical" href="https://faq.jokenetwork.de">