To my delight, while creating the Index (a.k.a. Keywords list) you can also make reference entries, like "overview, see <other term>" that simply refers the user to the correct index entry.  Easy:  just uncheck it in the keyword list.  It is meant to be read by the reader only, not double-clicked.  In this case, such an entry actually DOES serve two purposes:

 

1. if the person remembers the term "overview", this will guide him to the correct place in the index (in which case a link might be appropriate), or

 

2. if the user is wondering whether the material he is looking for is listed under "overview", then he will know quickly whether it is or is not, and can proceed accordingly.

 

I found that I did use a few of these in my index, but during my testing, I found I would be "put off" as a reader to be greeted by a message indicating my double-click didn't do anything.  So I also supplied links to the same links that would have been supplied had he gone to the more "correct" term. Simultaneously, my index entry serves to help the user to know that there IS a more correct term for that concept.