Additional directory structure on the ROM portion of a disc?

Question

Can I write an additional directory structure on the ROM portion of a disc?
I want directory "A" on the root level of the disc and directory "1", "2", and "3" within directory "A".
There would be various pdf's in the 1, 2, and 3 directories.

Answer 1

Yup!
This is called 'ROM Data'. You can add it from inside DVDSP but it often catches folks out in the way it works.
Basically, get your folder with the sub folders inside it, and the PDFs inside each subfolder. Make sure this is somewhere easy to find, like on your desktop. Name the parent folder something that your viewers will appreciate (like ROM, or "Additional Files' or 'MORE' or something like that).
At this point it is tempting to simply go to the property inspector and point the DVD-ROM settings at that 'parent' folder. However, this isn't what you do if you want to keep the folder structure intact.
Take your parent folder and put it (and all subfolders) into another folder. Now, go to DVDSP and click on the disc icon in the outline view, then look in the property inspector. On the first tab (General settings) you'll see the DVD-ROM settings towards the bottom. Check the 'Content' box and browse for the final folder you added everything to (the one with the parent folder and sub folders inside it).
When DVDSP builds your disc it will look inside this folder and put everything it finds at the root level of your disc, maintaining the folder structure. You will end up with your 'ROM' folder and three subfolders with PDFs inside it when the disc is created.
If you don't do the last step and you simply point to your 'ROM' folder, then you'll get three folders at the root level of the disc, and not the one single folder you wanted.