This filter adds an "external link" icon to links to outside websites . Well, it's not actually all that smart. It doesn't know what website it's on, so it adds the icon to any link whose URL starts with
https:. It also sets all external links to open in a new tab/window.
A link to another page won't have the icon.
If you try to combine this filter with the button links filter , make sure buttonize runs first. Otherwise, external links will not get styled as buttons when intended.