Q: Can I still use very old Apple Software Proof-of-purchase Coupons?

Hello.

I found my unused Apple Software Proof-of-purchase Coupons for my very old PowerBook G4's Mac OS X 10.2 preinstalled from the end of 2002. I didn't even know they existed. Oops! I didn't see any expiration dates on them. Can I still use these today to get discounts and stuff (like what?)?

Thank you in advance.