BMPCC4K Card/Reel/Mag number change ie B00x instead of A00x

Hi there,

Just got my new BMPCC4K and wondering if it's possible to label the card/mag I'm shooting on to B00x rather than "A".

I'm about to start a shoot and using my pocket cam as "B" camera, but it doesn't seem possible to change the card/mag label which is going to get a bit confusing for editorial...

any help is appreciated.