Here are two post from another forum regarding this very issue.
Jun 18, 2015
This was a response I received from Beretta because I also have the Model: PO9219FA
Product Description: 92-FA 9MM
Thank you for contacting Beretta Customer Support.
It means nothing sir. It is an internal "add on" so that the part number meets the minimum character requirement for our old systems. Anything marked "FA" is an F variant.
Best regards,
Beretta Customer Support
Jun 18, 2015
And then I followed up with this question
So is this model not a 92FS? but instead a 92F?
I thought the 92FS started in 1989, so I thought that mine would be a 92FS, but now I'm thinking it's a 92F.
This was there response:
Thank you for contacting Beretta Customer Support.
It was originally a 92F. To tell definitively, take the left grip panel off and take a photo of the hammer pin and send it to me. You will need to log into the online account to be able to attach the photo.
Best regards,
Beretta Customer Support