It appears that the docs for PDL::PP routines are not
being added to the PDL docs database. This makes
it difficult for developers or want to be developers
to discover the routines. E.g.,
$ pdldoc -a pp_line_numbers
$ pdldoc pp_addhdr
No PDL docs for 'pp_addhdr'. Using 'whatis'. (Try 'apropos pp_addhdr'?)
This was for PDL-2.4.10 on a cygwin/vista platform.
I don't believe the issue is platform specific.