JumpStart add pkg package

I have one question about Jumpstart Server.

I have OS Solaris 10 10/06 x86 on my PC.
I use NFS for share flar archives.
I create tftpboot macros for DHCP - dhcpmgr.
My clients file is here:

bash-3.00# more /jumpstart/solaris10/config/clients
install_type       flash_install
archive_location   nfs 192.168.50.100:/flash/S10arch.flar
partitioning       explicit
pool rpool auto auto auto any
bootenv installbe bename zfsBE

How can I add pkg package to clients file for instalation?