hull number

[luke-Korea]

Can someone tell me what this hull id means, ZFS82859M80B, ?
I know ZFS is for where it was made but puzzled by last M80B...?
Isn't this supposed to be month and year it was made?
looking for answer this hull number is from the seller.
Thks.

 

[Pop-n-Jack]

80 is the year and 82859 is the sail number