The message board is a great place to get quick answers and some direction, but if you really want to get the final word on IRS questions, you need to call the IRS. The reps are quite helpful, and if you ask them a complete stumper, they will even take your name and have an expert call you back. Don't be intimidated by the IRS. 1-877-829-5500, 7:00 am - 5:30 pm CST.
Here's a quote from the instructions of that section.
If the organization has not existed during the whole period the Support Schedule covers, fill in the information for the years that apply. If the organization's status is based on years not shown in the Support Schedule, attach an additional schedule for the other years.
I do recall at one point an IRS agent telling me that in general, don't leave things blank. If they don't apply, put N/A, then there's no doubt that you skipped a section. I'd probably scrawl something like "N/A - didn't exist" across those columns.
I didn't look at the details of the rest of the section (lower where it's one blank per line), but do complete it. So for instance if it's questions where you take one of the N/A fields and multiple it by a factor - still fill those fields with 0 or N/A. (That is not to say you need to pencil "N/A" in every individual cell of the support table. They'll get the idea.)
I also have the same question as lhaas. We formed in the year beginning 2007 and do not have any historical data for 2003-2006. I'm guessing we can leave the Part IV-A Support Schedule blank? Is this right?
I am also confused about Part IV-A, the Support Schedule. We became a 501(c)(3) last year -- 2007. So we don't have any historical information. Should I just write that we were not in existence on the form?