Implicitly defined anchors

The APT reference in the Doxia documentation says:

   "Section titles are implicitly defined anchors."

I assume this means I can create an anchor link to a section without  
having to explicitly define an anchor for that section.

I've tried to use this feature by putting the name of a top-level  
section between double curly braces (e.g., {{Installation}}), and it  
does create an anchor link in the HTML (e.g., <a  
href="#Installation">), but it doesn't go anywhere. There's no  
corresponding anchor in the HTML (e.g., <a name="Installation">).

It all works as expected if I explicitly make an anchor out of the  
section title.

Is this a bug, or have I misunderstood the documentation? Thanks,

Trevor