Hey Tychonoir, I'll look into these.

Note in the meantime that none of the database elements can be extended: 

if you declare an element with the same name as the vanilla data in your mod, it will replace the original, not extend it!

Name="AnomalyGenerationUnique_Default"

This list is ordered randomly, and up to WondersMaxQuantity of them is spawned (if there are less than WondersMaxQuantity, they are all spawned).

If there are no duplicates in this list, each should only spawn once. There can be only one of these per system.

They cannot be spawned on home systems, quest nodes, or the academy system. They have some Planet filters (not on destroyed/gas).

Name="AnomalyGeneration_Default"

The number of curiosities hiding anomalies from this list is equal to AnomaliesQuantity *GalaxyAnomalyAbundance.

They can be spawned several time if the random says so, and if some of them are also in the Unique list, they will spawn anyway (making them not unique).

There cannot be the same anomaly twice on the same planet, and there cannot be more than 2 anomalies on the same planet (I'm discovering these rules).

Note that if the AnomalyDefinition says it should be excluded from generation or random placement, the anomaly is not spawned.

Name="AnomalyVisibleGeneration_Default"

The number of visible anomalies spawned from this list is equal to AnomaliesVisibleQuantity.

They are spawned in a similar manner to anomalies hidden behind a curiosity, but before them. 

The generation order is: unique anomalies, strategic deposits (visible then curiosities), luxury deposits (visible then curiosities), anomalies (visible then curiosities), loot curiosities.

Once again, thanks for the info.

Ok, so there's the initial values based on galaxy size:

AnomaliesQuantity

AnomaliesVisibleQuantity

with multipliers based on settings:

GalaxyCurisotyAbundance

GalaxyAnomalyAbundance

You stated above that:

Curisoty anomalies = AnomaliesQuantity *GalaxyAnomalyAbundance

But visible anomailies = AnomaliesVisibleQuantity, with no multiplier

Therefore, only curisoty hidden anonalies react to abundance settings?

Yes! I don't know if this is wanted though...

I also saw that GalaxyCuriosityAbundance seems to be used only for the Loot curiosities, not for anything else...