Advance
Gold to Salt Trade
Some say that Salt is worth its weight in Gold... perhaps it would be more accurate to say that Gold is worth its weight in Salt. Either way, by exchanging these two commodities, we have established thriving trade networks.
SonghaiCountrypotentialAdvance tree
The game files don’t say where this goes: it has no requires, so the game places it in the 
Renaissance tree itself.
Modifiers
Trade Advantage+10%
Definitionin_game/common/advances/country_SON.txt:20
22icon = markets_for_salt