=item pkgnum - package (see L<FS::cust_pkg>) or 0 for the special virtual sales tax package, or -1 for the virtual line item (itemdesc is used for the line)
=item pkgpart_override - optional package definition (see L<FS::part_pkg>) override
=item pkgnum - package (see L<FS::cust_pkg>) or 0 for the special virtual sales tax package, or -1 for the virtual line item (itemdesc is used for the line)
=item pkgpart_override - optional package definition (see L<FS::part_pkg>) override
-=item type - can be set to U for usage; more later