孩子持綠卡入關時，護照上加蓋了WT。請問WT是什麽意思？我們想去一趟加拿大，回美國會有問題嗎？
-As far as I know, WT or WB means soemone from a country that does not need a visa to enter the US (visa waiver program) and thus, the CBP officer at the port of entry put WT/WB on the passport to indicate this person is a visitor (tourist or businessman) under visa waiver program.
So, it seems the CBP officer was confused in your child's status. Your child had better go to the CBP local Deferred Inspections Office to fix it in case there is any potential issue.
