You may want to index some term, but the problem is, pointing to what in the XHTML index ? Hereunder, I do <emph>-asise the two terms to be indexed. Both appear indeed in the index, but only the first one points to somewhere. The circumstances are explained in the two following sections.
The combination of elements <index> (without attribute) + <term> was giving in the index an entry about the term
Most of the time, this still happens.
But if the parent <p> element of the <index> + <term> elements happens to have an XML identity (but no heading), the index
A pointer without content in XHTML only appears as a pointer in the XHTML code, but is no pointer in the page : there is nowhere to click to activate the pointer.