What do all these letters/numbers in early Samsung ROM file name mean? This question covers early Samsung ROMs if your ROM looks like this example G930FXXU2EREM_G930FOJV2ERE8_TUR.zip then see this updated question here

I'm guessing the first 5 letters/numbers are for the model of the device I8160XXLL2, but what after that? Is there any guide to understand what exactly they mean by these letters? I'm confused it seems sometimes they repeat the model of the device twice?
I8160XXLL2_I8160QXXL3.zip
I8160XXLL2_QXELL3.zip
These 2 firmware names are a good demonstration of (early) Samsung naming conventions.


I8160XXLL2 is the "PDA" designator, i.e. build number;
I8160QXXLL3 is the "CSC" designator, i.e. baseband version.


There can be multiple CSCs corresponding to a single PDA, released for different regions.

Inside the string:


I8160 is, obviously the model number;
XX is for country/region (XX itself means Europe or international);
LL2 are the release date and version (within same month): first L for year (L for 2012, M for 2013, etc.), second L for month (A for January, L for December, etc.), and 2 for the 2nd version.


Furthermore, you can pinpoint which exact region the firmware is for by using a part of the CSC: QXX/QXE designates the precise region within the one defined in PDA. Match these 3 digits with a list of firmwares (e.g. on SamMobile), and you will know what regions received such releases.