If you're gifting 500 mile certs, remember that the recipient must be traveling on a full Y fare if they are not a Premier and not traveling with you.

I don't think that there is anyone, not a single person at United, that can complete all the necessary computer entries to transfer an upgrade certificate to another traveler you designate. But even the kids collecting stray luggage carts will warn you that 500-mile certs require a full Y ticket for non-premiers... To upgrade a non-premier you MUST use HK49 unless they're on full Y.