In the Specific Links tab, specify any number of topic, hypertext link, or index entry objects to add to the related group at publishing time.
Use the shortcut menu to add topics.
Add hypertext links and index entry objects by dragging the link into the tab.
Sets a relationship between this topic and one or more other topic, hypertext link, or index entry objects that are included in this related group. Hypertext link and index entry objects resolve down to the topics they are linked to.
Any specified topics that are not a part of the book are ignored at publishing time. Hypertext links to URLS or external files won't resolve.
Combining or separating special and specific links in the published output
Combine a list of special links, for example, child, sibling, or parent topics, with a group of specific links by assigning the same "group heading" to both lists. When you publish, the objects are added to the same list. If you use more than one group, and the group headings are different, then separate groups are created when you publish.