I know that purchased upgrades never expire, but are they transferable? Do they have a passenger name on them?

The last time I bought upgrades were in the USAir days. I up until recently had some really old, yellow USAir First Class upgrade coupons. They never expired and didn't have my name on them, so I gifted them to a Silver short of coupons. Those were transferable but that was a long time ago, so I'm wondering if purchased upgrades are still transferable.