> Sponsorships (unless demarcated "includes paid promotion")

I believe this policy came about due to FTC legislation that came into effect some time in the late 2010s or early 2020s. There was definitely a period in the 2010s when YouTube allowed sponsorships without the need to disclose them, or at least wasn't enforcing any policies they had against it.

> IRs are still against the rules today.

What does IR stand for?