-Cross-reference links in the manual are reasonably stable, since they are
-independent of the ordering number (which gets removed from the URL) and the
-pretty page title (the URL is created from the file name). So unless a file
-is renamed or moved to another sub-directory, links should be ok.
+Internal manual links should be absolutely stable, as long as the references in
+the master document do not change (and they absolutely *should* not be changed
+except for a *very* good reason, even then they probably should not be
+changed!). Use the form:
+
+<a href="@@my-internal-link">
+
+where @@my-internal-link is a reference to a "link:" keyword in a header in the
+master document. Note that in the master document, they will not have the
+double at-sign ("@@") in front, that is *only* used in the page content to
+signal to the build system that it is an internal link that needs to be fixed
+so that it points to the correct URL.
+