But the main problem is that for isHeader() uctags defaults to TRUE for an unknown file extension which is what I'd like to change.
Ok, since Geany can't distinguish header from body (in the actual language there _is_ no distinction, a "header" is just what programmers call a C/C++ file that meets some idioms that allow it to be included multiple times in client and body files without generating multiple declarations or vast repeated quantities of code/data) I guess the only distinction is uctags version, however good (or not) it is.