Googled this and couldn't find any information. I have a GFCI with date code 9J26L. Looking up recall data online from 2005 and 2019, I was able to figure out that the second character is the month, in this case September, and the third character is the week of the month. But I can't figure out how to get the year from characters 1, 4, and 5. Any ideas?

I think maybe the first character is a year. With a 9 being 1990, A being 1991, B being 1992, all the way to Z being 2017, and restarting at 0 for 2018. This might be one or two years off.
Anyone have known devices to compared to?

hey you should move this to dating and specification.

hey you should move this to dating and specification.

Okay, done. I never knew that form was here, looks like it's new.