I just got thru the 3080 ti ftw3 ultra hybrid queue (i jumped in on launch day at 8:22 AM and finally got it popped), and is looking to sell my old 2080 ti black locally.
I see that had I gone thru with ebay the other guy can just use that as the invoice, but since I am looking to sell local (either via internal company slack, friends, reddit hardwareswap, or craigslist), what do I need to provide the new owners so that they have the rest of the 3 year warranty?