Anybody out there know their Mini DV tapes by any chance...??

I've been using Panasonic DV tapes for my Xl1s and XM2 for some time.
They were boxed as:
Panasonic AY-DVM60EF (DVC 60's)

I've now bought through another dealer some:
Panasonic ME-DVM60 (DVC 60's)

Am I being a bit picky...but are these essentially the same tape (and therefore safe to use in my cameras as I want to keep the same brand/manufacturer), or is there a significance to the AY pre fix?

Any ideas>?

Thanks

Perhaps it is best to contact Panasonic with this question? I doubt
anyone outside Pana knows exactly what the differences are....