If we specify a topic index by IndexPage, we can take advantage of the search index. In IndexPage we can provide a set of html index pages along with the structure type of the index. The type of the index could be:

<DIR> <LI> ... </DIR> (default)

<UL> <LI> ... </UL> (only one level of <UL>)

The first is the one generated by texinfo.

For instance:

IndexPage html-version/gid_18.html html-faq/faq_11.html