Originally Posted by
YYC009
1) It depends if 'OSS' is marked on the boarding pass. If the previous carrier doesn't participate in the program, then there is no IT infrastructure to print 'OSS' on the downline boarding passes.
2) Definitely possible. It is not a foolproof system. As others mention, there is nothing stopping a PEK-YYZ passenger who is not OSS eligible from handing something off to a DEN-YYZ passenger who is OSS eligible on the way to the Customs Hall.
This is behind not being "foolproof".
This is literally pointless and stupid. If a sterile and unsterile passenger can hold hands, neither of them are sterile.