Hi,

some weeks ago I was looking for C/2016 R2 (PANSTARRS) in KStars but I couldn't it. So I checked the comets.dat and it seems there are only ~443 comets in the list which are all periodical. So I looked up the JPL query and there is a filter on ksutils.cpp:1253

QByteArray query("obj_group=all&obj_kind=" + kind + "&obj_numbered=num&OBJ_field=0&ORB_field=0");

obj_numbered is set to "num" which means there are only official named comets selected:

And finally, the numbered state can be "numbered" (meaning the object has been officially numbered by the IAU) or "unnumbered"
( ssd.jpl.nasa.gov/?help_sbdb_query )