Legend - Type List - Updates
TradeableItems:
-1 = TRADE_ITEM_NONE
0 = TRADE_GOLD
1 = TRADE_GOLD_PER_TURN
2 = TRADE_MAPS
3 = TRADE_VASSAL
4 = TRADE_SURRENDER
5 = TRADE_OPEN_BORDERS
6 = TRADE_DEFENSIVE_PACT
7 = TRADE_PERMANENT_ALLIANCE
8 = TRADE_PEACE_TREATY
9 = NUM_BASIC_ITEMS
10 = TRADE_TECHNOLOGIES
11 = TRADE_RESOURCES
12 = TRADE_CITIES
13 = TRADE_PEACE
14 = TRADE_WAR
15 = TRADE_EMBARGO
16 = TRADE_CIVIC
17 = TRADE_RELIGION
18 = NUM_TRADEABLE_HEADINGS
18 = NUM_TRADEABLE_ITEMS