What is the meaning of KDZ file name format? What is the meaning of LG's .kdz file name format?

For instance, a KDZ file: D85530B_00_1217.kdz (Marshmallow for LG G3 D855).

After the model no (D855), the terms like 30B, 30C etc. are coming. What does it mean?
KDZ is the format which LG uses when posting official firmware releases on their website. KDZ are all stock releases from LG. Custom ROMs do not come as KDZ, the tend to come as ZIP file.

KDZ files are flashed with LG Flash Tool or LGUP, and ZIP files are flashed with TWRP.


10 means KitKat
20 means Lollipop
30 means Marshmallow


A/B/C/etc is revision number.

1217 is the release date 17-Dec.

It can be confusing because there are many different versions of D855 for different carriers and regions, with different revision numbers.

For example in the UK, the latest O2 Lollipop version is 20n, but the latest unlocked Lollipop version seems to be up to 21c, but both are up to date with the latest Android security patches.