The 20 digit serial number will tell us when it was manufactured. That will tell us how long the non-Dell store had it in their warehouse. We are up to revision A03 so I hope that is what they sold you. If not, you should return it and purchase new directly from Dell. There is only one model. The small b is the Dell notation of the factory. I am not sure when the cut in date was, but we are starting to add service tags to all monitors worldwide.

It's manufactured in January 2016 and the revision seems to be A03, so it must be the legit latest version I think.

Actually I got to wonder all about this after I found a stuck pixel (always green) on the center of the screen. I was asking my retailer on this issue, but also wonder if I could get service directly from Dell.

If you see the stuck pixel on an all black screen, yes, Dell could exchange it.
If you only see the stuck pixel on an all white screen, no, you would need 6 or more dark pixel defects to get an exchange.

Personally, I would return it to the seller and buy a new from Dell directly. Your call.

I tried to register my monitor through "Retail Registration", but only to receive an email from Tag Team that says it's denied because tag does not exist. Then I called tech support and customer support or some multiple departments and talked to almost 8 person, but nobody managed to resolve my issue.

Meanwhile, I found my P2415Q has a part number 1492V which is different from Y9PCD listed on the official Dell website. Only 1492V I could google was a refurbished one sold by Dell Outlet.

Could you confirm any of this information and also help me to register my monitor for warranty lookup?

By the way, I found my package box has a different part number listed on. It is "CN-0G3D7F-xxxxx-613-xxxx". The monitor itself has "CN-01492V-xxxxx-613-xxxx" on the back. Other digits are the same. It also has the same service tag.

Update (04/05/2016): The Color Calibration Factory Report also reports its S/N to be "CN0G3D7F...".

Would that mean we could have different part or serial numbers in the package and the monitor? The enclosed Color Calibration Factory Report also states its S/N to be the same as the package, but different from the monitor itself. Could you verify my PPID serial number for its original region and warrant status? I can send you one via private message.

There is no problem with the part numbers. In fact, we have 10 different part numbers for this monitor all based on region. If Dell support in your region could not identify the service tag number, this means it was originally sold out of a different region of the world. If that is the case, you cannot register it with Dell. You and Dell support for your region would follow this warranty policy =

Discussion:
The customer is unable to provide a Dell Order number or Service Tag number or the Service Tag number fails to appear in your region

Warranty Length:
3 years from the monitor manufacture date embedded in the 20 digit PPID serial number

Replacement Procedure:
Set up the monitor replacement against the dummy tag

* You would provide the following data to the representative if you ever need a monitor replacement within that 3 year period:
Brick or Online Store:
Monitor model:
Monitor 20 digit alphanumeric PPID serial number:
[Your]
Email address:
Name:
Shipping address:
Phone number:
Operating system:
Video card:
Video card ports tested:
Issue:
Troubleshooting performed:
* Monitor Factory Reset done
* Monitor failed Self-Test and Built-in Diagnostics
* Post further troubleshooting

By the way, it also reminds me of that the Part# "1492V" (refurbished Dell P2415Q with 90-days warranty) was actually sold by Dell Outlet store here in the US last year. I'm now confused with your saying that my product would have been sold out to other regions than US given that it has the same Part# used to be sold in the US.

The serial number is not recorded in our systems. Only the Dell Customer number, Order number, and Service Tag number. But if the Service Tag number were sold out of our Asia Pacific region, my Americas tools would not see it. I'm saying it may have originally shipped from one region, then a seller sold it to another seller in another region. Honestly, you would be better off returning it to the seller and buying new directly from Dell. Read this. Send me the serial number and service tag number via private message and I will see what the tools state.