Hey all, 

I'm guessing that this is probably not going to be answered here but I figured I'd ask.
I've noticed on Atlus GBA prototypes, there is a sticker, always the same size, always the same font, that says "F01" or "F13" or "F12" or "F09"
Does anyone know what they are for? I've seen about....I'd guess....12 GBA Atlus prototypes, all of them are long board design, rather than medium length with a case, or small cart. 5 of these protos I haven't been able to make out the lettering/numbers on because the SRAM board was blocking the sticker, or low-ish quality pictures. An example is listed as an attachment.
Does anyone know...is it a version? an overwrite amount? a serial number? Any ideas? They've been different on all the GBA Atlus protos so far that I've been able to recognize.

EDIT: My current running theory is that its an write amount. so F01 is on its first write, F13 is on its 13th write, etc. Not sure what the F means though..

"F" could mean "flash"

Thats part of why I was thinking it might be the number of times it has been written to. I say this because these flash carts were wiped clean with UV light. So it was flashed, and then overwritten. However, it could also be that its flashcartXX resulting in being a serial number or registration number of sorts.