Some basic PKG-handling commands follow:
To add a package:
pkgadd -d package_name.pkg
To remove a package:
pkgrm package_name
To get a full list of installed packages:
pkginfo
To get detailed information for a package:
pkginfo -l package_name
To list the files belonging to a package:
pkgchk -v package_name
To get packaging information for an arbitrary file:
pkgchk -l -p file_name