Inspired by recent question about difference between two Lumias, I wonder what are the general rules in the Lumia numbers. (including those ?rare? numbers like 928 etc).
General rule of thumb:
The first number (or the first two numbers for four-digit models) indicates the family. Higher numbers denote higher-end models, so a 9xx series device is going to have better specs and build quality than, say, a 6xx series device (of the same generation).
Large screen devices (or "phablets") initially used numbers higher than 10, and should be considered to have their own hierarchy. For example, the 1320 is not higher-end than the 1020, despite the fact that 13 > 10. In 2015, though, Microsoft added the XL suffix to denote phablets and might discontinue the practice of four-digit model numbers.
The next number indicates the generation:
- Numbers 0 and 1 indicate a first-generation device that originally shipped with Windows Phone 7 (with the exception of the Lumia 810, which is a second-gen device). For example: 510, 710, 900.
- Number 2 indicates a second-generation device that originally shipped with Windows Phone 8.0. For example: 520, 920, 1020, 1520.
- Number 3 indicates a third-generation device that originally shipped with Windows Phone 8.1. For example: 630, 930.
- Number 4 indicates a fourth-generation device that originally shipped with Windows Phone 8.1. For example: 640.
- Number 5 indicates a fifth-generation device that originally shipped with Windows 10 Mobile. For example: 550, 950.
The last number usually differentiates between minor variations within the same family and generation. A device with the model number ending with 0 is the base model (e.g. 920, 630), while non-0 can be a refined version (925), a 4G variant (635), or a carrier-specific model (928).
Model numbers can also optionally include letter suffixes:
- The letters C and T, unspaced, indicate versions exclusive to China Telecom. For example: 800C, 920T.
- The suffix XL, spaced, indicates a larger version of the device, usually with a minor upgrade in specs. For example: 640 XL or 950 XL (larger versions of the 640 and 950, respectively).
Of course, there are a few oddball models, like the Icon (Verizon-exclusive variant of the 930, actual model number 929) and 2520 (a Windows RT slate), but overall the above should cover pretty much all Lumia devices released so far (for a full list of them, see Wikipedia). As of right now, it seems this naming scheme will continue under the Microsoft Mobile brand, with only a few minor changes.