That means it's linking to the 24th "doc fragment", or in other words the 24th .xhtml file within the EPUB. It's supposed to be there, otherwise it wouldn't be able to find it.
What you're doing wouldn't work anywhere because you're supposed to link to id="place_01". It's generally recommended to use that like:
Code:
<h2 id="place_01">CHAPTER TITLE</h2>
Rather than sprinkling in meaningless elements in the general vicinity of what you actually want to refer to.