Qt Creator's contextual help system doesn't seem to lookup identifiers in third-part helps.
Normally when you press F1 over a Qt identify it opens the appropriate help page. I wanted to extend this to the linux C library man pages (and C++ & OpenGL in future) so I converted them all to HTML and wrote a simple .qhp file for them with some example keywords like this:
<keyword name="fread" id="fread" ref="man3/fread.3.html"/>
The resulting .qch file is successfully opened by QtCreator but the context help doesn't work (just says "No documentation found."). I tried various variations on std::fread, fread(), etc. None worked.