title: Documentation not appearing in doxygen output
body: <p>I'm trying to document a C API which is all contained in a single C Header file. When I run doxygen, on the file, it's giving me errors for currently undocumented C Macros, but when I add the necessary documentation for macros, although the undocumented errors are cleared, the macros plus documentation do not appear in the doxygen generated html output.</p>
  
  <p>Only a fraction of the documented header file, the structures, actually appears in any doxygen output. I can't see anything in configuration settings or documentation that would assist in clarifying why doxygen does not place documented code from the header file into its generated output. </p>
  
  <p>Does anybody know why this would be the case?</p>