Got little ones on heavy paper, with a form date of 12/00. "You may use ... anywhere United flies. Stopovers not permitted." Interesting thing is that L, S, T, K, etc fares are not listed as either upgradeable or nonupgradeable.
J: if your kind certificate advance arrives in time for me to use, I'll get these to you by mail or if you can wait until the 1st wk April, in person (then you get an extra 5 months! plus no HI restriction).