Do all Rolex watches have a serial number?

Related questions

1. What is a Rolex Oyster Perpetual?
2. Can Rolex watches be traced?
3. How can I tell if a Rolex serial number is real?
4. Does a Rolex hold its value?
5. Is a Rolex Datejust a good investment?
6. Does a Rolex tick?
7. Can you tell if a Rolex is stolen?
8. Where is the serial number on a Rolex Oyster Perpetual Day date?
9. Does Rolex have a lifetime warranty?
10. How much is a Rolex Oyster Perpetual Datejust worth?

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20. #serial