Since its 2013 version, Canonical Tags in SharePoint are supported by default if you enable the Publishing Feature. You can also use Managed Navigation to have Friendly URLs and make your canonical tags look awesome!

These Canonical URLs are important to help Search Engines on their task for categorization, simplifying tracking metrics and consolidating links and references that may have different URL formats, but point to the same page. You can find more info in this post.

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