Terrible change. United, if you want to enable better tracking, then do away with the paper altogether. Switch to electronic upgrades and let us request upgrades online. Otherwise, let us please go back to the generic certs.

Some of us choose to have a stack of paper certs and use them as opportunities arise, and as far as I know this is a completely acceptable use.

Case in point, once I was rerouted on LH after my flight on UA went MX. I was able to upgrade on the spot. The new system makes it impossible.

If you want to kill this benefit, then say so.