It is true that for a lot of these, I can simply look at the bottom of my browser as I move the cursor over the links to see where the link will take me. But then the Readability of the document is compromised, and even with this mechanism, there is no way to tell the difference between footnote links, definition links, or any other type of link to documents at the same site.
Link-Type Distiction says simply that there should be some kind of visual distinction between different types of links. HTML offers no standard way of providing Link-Type Distinction; this is problematic. Most browsers now handle one type of link distiction; they color a link differently if you've already visited the link's document. But that's a function of the browser, not of HTML. At this site, I differentiate between two types of links: links to this site, and links to other sites. Links to other sites are italicized; links within this site appear normally.