This is a WORD (docx) index. It contains the item used in the other sections.
In order of items references to appear in this section, the sections in which they appear need to be configured accordingly.
This section is based on word features, it appears only in PDFs and DOCX documents not in HTML.
Specific Options of Item Reference Section
The word formatting defined in the options is passed on to word. Find in the documentation of your version of word what the options are.