The switch hacking community has been trying to understand which Firmware consoles ship with, based on their serial numbers.
Data on this for now is very limited, but it is already known that up to firmware 3.0.0 included, the Nintendo Switch is hackable, however firmware 3.01 patched a critical vulnerability. Today, all new Nintendo Switch consoles on the market ship with firmware 3.0.0 or below, but at some point in time, probably sooner than later, models with firmware 3.0.1 or above will start hitting the market. People looking for a lower firmware will therefore need this valuable information.
According to user CTCaer on GBATemp, a Nintendo Switch serial is composed of 5 digits/letter that indicate manufacturing information that’s irrelevant to the date it was manufactured (see below), followed by actual information on the batch. Specifically:
X: From NX. It’s actually the platform code. A: It’s the hardware code. A: Switch, B: Joy-Con (L), C: Joy-Con (R). And I assume D for Pro (check the plastic sliver that came with, if it exists). J/W: West or Japan? Probably the region that was supposed to reach. Maybe with all the pre-orders and the after-launch demand, they just sent them everywhere to keep people happy. Or, at some point they weren’t Region-free. 10/14/40/70: Factory made or assembled?
User Essometer gave an additional example:
For example: XAJ70002712345
X: Product of NX line A: Switch Hardware J70: Assembly line The following numbers are probably a consecutive number. So the Switch in the example is Switch number 2712345.
The people driving the effort in the community hope that the numbers will help giving estimates of what firmware the console ships with. This is assuming those numbers are consecutive or grouped by batches.
So far the initiative has only gathered a limited number of replies, making it difficult to make any guess. People might be worried to share their serial number, so for now the original poster on GBATemp recommends to just share the beginning of the number. A shared spreadsheet has been put in place, which at the time of this writing only has a bit more than 50 entries. Sadly not enough to make a good guess yet. You can participate and add your own Switch’s data if you feel like helping the cause!