Q:

Install GRUB(2?)  to PBR or MBR? ( Intend to chainload Lubuntu from Syslinux/ISOlinux)

I have installed Fatdog64 on a re-purposed laptop, and am trying to install Lubuntu alongside Fatdog in a multiboot setup.  However, the Fatdog install is not recognized by the Ubuntu Minimal installer, and thus is not offering an option to multiboot into it with GRUB.  I've had GRUB(2) nuked by Ubuntu updates before, and I've been practicing with Fatdog on a USB install, so I'm more comfortable with the Syslinux bootloader than GRUB.  Thus, I'd like to install [L]Ubuntu without putting GRUB on the MBR.   
I understand some about MBR and bootloading, having chained to/from GRUB, GRUB4dos, sys/isolinux, and Windows, but I realize I don't actually understand how Ubuntu boots, and if it must be booted from GRUB (and thus requiring GRUB somewhere on the system, and hence the PBR if not the MBR).  I also know there is a "Maintenance-Free" custom GRUB screen how-to (help.ubuntu.com/community/MaintenanceFreeCustomGrub2Screen), but at this juncture I'd rather stick with the iso/syslinux setup so that I can reuse the knowledge in USB/CD booting setups I am concurrently utilizing. 
Since I want to keep Syslinux on the MBR (Master Boot Record), does GRUB need to go on the PBR (Partition Boot Record) where I installed Ubuntu, or does it just not get installed?  

A:

Referencing the syslinux.org documentation, chain.c32 can direct booting to a particular bootloader and particular partition.  In my case, Lubuntu booted by simply using ...
COM32 chain.c32 
APPEND hd0 5
text help
   Boot into Lubuntu
endtext

... as Lubuntu created a logical partition and installed itself on the first partition therein (usually the first partition in a logical partition is designated the fifth partition). 
I believe this could be used to boot other OS installations by sending the boot sequence to the partition, and if necessary, specifying a loader (such as ntldr for windows)
Perhaps my original question came from a confused perspective - I wanted to still chainload GRUB from syslinux.  Although this [text above] answers how to boot into Lubuntu using the Syslinux I have as MBR bootloader, I'd still like to have GRUB (or GRUB2) on a different partition, so that I can play with that installation and learn by doing.  I'm open to direction on how to do that, and will happily mark that as the answer to my question. 
Edit to add: Referencing this blog post, there are options to cross-chain-load many different boot loaders.  I'm just trying to get Syslinux to chainload GRUB.