Aha. I just consulted with my No. 1 Son who showed me exactly that. So I've learned something today

I note this trick works with some links but not others. In spite of his expertise, however, he says he doesn't know exactly where that text in the yellow box comes from. Also i'm not cleear what's the difference between a hot link and a cold one. Can I conclude that the cold one is black and non-clickable where the hot one is of course in color and clickable

Edited to add my No. 2 Son explains that the little box only appears only with a link to a post within the same site

Although he's much more versed at this kind of thing than I (nearly anyone else is) he also doesn't know what it is that makes a link hot so I looked it up--

Inline linking (also known as hotlinking, leeching, piggy-backing, direct linking, offsite image grabs and bandwidth theft) is the use of a linked object, often an image, from one site into a web page belonging to a second site. The second site is said to have an inline link to the site where the object is located.

Can I conclude then that a hot link is a means of linking to a specific post or passage at a different site whereas a cold link is merely a link to the address of that site