Reference middle name or middle initials?

I’m filling out my e-QIP and am finding that for one of my references I do not know their middle name or middle initial. For now I have left it blank (“NMN”). I’m waiting to hear back from my reference (neighbor) for confirmation, but I was curious how important this information is for the investigation? Assuming that I have everything else correct including contact information.

It has no impact at all on the investigation.