PayPal shipping label tracking number query

[kriswoj]

I sell quite a few things with paypal as payment and buy the shipping label through paypal due to the convenience.

However, I notice that when I buy services such as Internaltional Standard with Royal Mail, a service which has no tracking involved, paypal add a tracking number to the "track your delivery" info... it always seems to start FF then the numbers , e.g. FF002921970GB

I'm extremely puzzled, as the shipment has absolutely no tracking involved, so where does this "tracking" number come from, what does it do, why is it there? It's confused a few people who were receiving the packages from me as they've complained to me that the tracking info doesn't work (of course it doesn't, the package isn't being tracked at all).

This FF tracking number appears in literally every shipping label purchase I make. It doesn't appear on the actual label, just on the info screen for the paypal transaction. 

I would add a screen grab, but can't see any way to do so. 

Any help would be appreciated!!

[kernowlass]

@kriswoj

Do you use Firefox browser, because FF could be that you are printing the shipping label using it.

[kriswoj]

@kernowlass No, I use chrome. The number appears in the tracking info part and exactly matches the format used by postal services: 2 letters, 9 numbers, then 2 more letters.