A work permit issued by Canada has some numbers that are not labelled explicitly.
- an 11-digit number (like BB123 456 789) in red ink at the top right, in a rounded box
- a 10 digit number (like U123456789) in black ink below the rounded box
There are also these labelled numbers:
- OFF. FILE NO (like W123456789)
- CLIENT ID. (like 1234 - 5678)
Which of these numbers is the Work Permit number? And what are the other unlabelled numbers called?