I understand from Interpreting AC Delco's manufacturing date for car batteries and other posts that the manufacturing date for AC Delco batteries is encoded in text on the top sticker starting with 'P' or 'S'. However, I can't see any codes matching this on my battery.
The only codes on the top are '19', and 'Dk 84911'. On the side appears to be IHR31. See photos below.
Is there a different standard for Japanese batteries?