[CentOS] grubby question

I am looking at using grubby. My command is:

grubby --grub --title "CentOS (2.6.32.60)" --add-kernel=/boot/vmlinuz-2.6.32.60 --initrd=/boot/initrd-2.6.32.60.img --args="ro root=LABEL=/ noapic" --make-default

my etc/grub.conf file after running the command is: title CentOS (2.6.32.60) kernel /boot/vmlinuz-2.6.32.60 ro root=LABEL=/ rhgb quiet noapic initrd /boot/initrd-2.6.32.60.img title CentOS (2.6.18-308.4.1.el5) root (hd0,0) kernel /boot/vmlinuz-2.6.18-308.4.1.el5 ro root=LABEL=/ rhgb quiet noapic initrd /boot/initrd-2.6.18-308.4.1.el5.img

Notice the "root (hd0,0)" is not there... What option creates that entry, I did not see it?

Thanks,

Jerry