InDesign ::: Adding Table Of Contents To Indesign Book, .indb file

1. I created all of the individual files including a table of contents in an .indd.

2. I created a Book (.indb) with all of the .indds in it.

3. I then went back into the .indd containing the table of contents, clicked Layout>Table of Contents and then saw that the “include book documents” box which was not previously available was now available to be selected.