The serial should be stamped at the end of the board like your RR1. That said, mistakes happen so while unlikely, it is possible that it left the factory without getting stamped. Or if the fingerboard was ever leveled the serial could have been ground away. Or it could be an old employee project. Do you have a pic?

Stolen guitars often have serials removed, did you buy from a store?

Pics would help. I have a 1985 Soloist with no serial number, probably first Hot Rod Flames Soloist ever made. I'm guessing it was an employee project.

My first thought would be production mistake. Enough guitars without serials exist for me to think it's the most likely answer.

The numbers are die punched so even a fretboard board plane isn't going to completely obscure a serial number without leaving some evidence.

And I've seen a few examples of Jacksons with serials obliterated. They're all fairly obviously scrubbed.

If it didn't get stamped, the only thing you could hope for is having the hang tag.

If the work order number is on the guitar, it might be possible to get a serial number. If Fender is willing to dig around for a few seconds... don't hold your breath.