Happily doing the OLCI and after clicking continue I was warned that I need to enter "Secondary Documentation" for US residents only. In the past you can leave that blank and just continue with primary passport information. Anyway, no biggie I said, until I clicked the drop-down menu, it only gave two choices: "Alien Registration Card" (which as US Citizen I don't have) and "US Permanent Residence Card" - WHAT THE HECK IS THAT! I have grew up in the USA and the only times I've read of such things in the news, and it's usually related to voter fraud and how people that don't have Driver's License can apply for such Residence ID. Because in the USA your Driver's License or Social Security Number, and its respective numbers, pretty much serves as information that is equivalent to HKID#. USA is unique in that area. So, since I have only two choices, I clicked Residence ID and typed in my Driver's License number and expiration date, but CX should really realized this will confuse the heck out of a lot of US citizens.