Thank you! I forgot to add the link to the source code, I updated it now. You can find it here: gitlab.com/picolisp-blog/web-applications/-/blob/…

To answer your first question: The <href> goes into the recursive list where all children and couples are printed (see source code).

To answer your second question: "Displaying a link" just means that instead of a list of names you get a list of links. So if you click on one of the names, it will open a new family tree of this person. I think it will be more clear if you try to run the example on your own...