Play Store Early Access and investor referral code?

I been trying to research a bit about the Google Play Store Early Access program.

I understand that I have to fill a form for nomination.

https://docs.google.com/forms/d/e/1FAIpQLSdgQwWmvkuH3kKvhmrzOSDk_MPihEBe7HMLNelREO_Kgkc9Dg/viewform

Upon review, I see a section called "Investor referral code (if applicable)"

Can someone let me know what this is? I've tried to search everywhere to find any information about it but hit a dead end.