By default, the following tag shows up in every WordPress install.
<link rel='shortlink' href='https://domain.com?p=712' />
This is used for a shortlink to your pages and posts. However, if you are already using pretty permalinks, such as domain.com/post, then there is no reason to keep this, it is just unnecessary code.
Follow the steps below to remove shortlinks.
Click into the Perfmatters plugin settings.
Make sure you’re on the “General” tab.
Under the “Options” section, toggle on “Remove Shortlink.”
Scroll down and click “Save Changes.”
This also removes the
rel=shortlink HTTP response header associated with it.