WordPress.org

Author: Thaya Kareeson

This simple plugin helps you easily tell the search engine bots the preferred version of a page by specifying the canonical properly within your head tag.

Why would you do such a thing? Simply because many black-hat SEO folks abuse duplicate content to gain search ranking and search engine try really hard to detect and penalize them. The last thing you want to do is present yourself as an SEO spammer to search engines.