CfgWorlds is usually the largest class in the config file, as this is where the "meat" of the island configuration is. These are the classes defined in CfgWorlds, with some specific ones from BISampleMap and Chernarus:
CfgWorlds | |- DefaultClutter | |- DefaultWorld | |- CAWorld : DefaultWorld | |- Grid | |- SampleMap : CAWorld | |- Grid : Grid | |- Zoom1 | |- Zoom2 | |- SecondaryAirports | |- ChernarusAirstrip1 | |- (...) | |- ReplaceObjects | |- Sounds | |- Animation | |- Lighting : DefaultLighting | |- DayLightingBrightAlmost : DayLightingBrightAlmost | |- DayLightingRainy : DayLightingRainy | |- Weather : Weather | |- Lighting : Lighting | |- (...) | |- clutter | |- GrassGeneral : DefaultClutter | |- GrassFlowers : GrassGeneral | |- (...) | |- Subdivision | |- Fractal | |- WhiteNoise | |- Ambient | |- BigBirds | | |- Species | | |- Hawk | | | |- (...) | | | |- WindClutter | | |- Species | | |- FxWindGrass1 | | |- (...) | | | |- NoWindClutter | | |- Species | | |- FxWindPollen1 | | | |- SmallInsects | | |- (...) | | | |- (...) | |- Names | |- SampleMapVeg_1 | |- (...) | |- Armory |- (...)Some of these are self-explanatory, others not so much. Some are probably not even useful on custom islands, and in fact you can make a working config without many of these classes.