diff --git a/constants/script_constants.asm b/constants/script_constants.asm
index d4543f05..afd1258b 100644
--- a/constants/script_constants.asm
+++ b/constants/script_constants.asm
@@ -22,7 +22,7 @@ DEF SLOTS_SOMEONESKEYS EQU $ff
 	const_def
 	const TRADE_FOR_TERRY
 	const TRADE_FOR_MARCEL
-	const TRADE_FOR_CHIKUCHIKU
+	const TRADE_FOR_CHIKUCHIKU ; unused
 	const TRADE_FOR_SAILOR
 	const TRADE_FOR_DUX
 	const TRADE_FOR_MARC
@@ -36,7 +36,7 @@ DEF NUM_NPC_TRADES EQU const_value
 ; InGameTradeTextPointers indexes (see engine/events/in_game_trades.asm)
 	const_def
 	const TRADE_DIALOGSET_CASUAL
-	const TRADE_DIALOGSET_POLITE
+	const TRADE_DIALOGSET_EVOLUTION
 	const TRADE_DIALOGSET_HAPPY
 
 ; badges
diff --git a/data/events/trades.asm b/data/events/trades.asm
index 560abfa1..b230a918 100644
--- a/data/events/trades.asm
+++ b/data/events/trades.asm
@@ -2,14 +2,18 @@ TradeMons:
 ; entries correspond to TRADE_FOR_* constants
 	table_width 3 + NAME_LENGTH, TradeMons
 	; give mon, get mon, dialog id, nickname
-	db NIDORINO,   NIDORINA,  TRADE_DIALOGSET_CASUAL, "TERRY@@@@@@"
-	db ABRA,       MR_MIME,   TRADE_DIALOGSET_CASUAL, "MARCEL@@@@@"
-	db BUTTERFREE, BEEDRILL,  TRADE_DIALOGSET_HAPPY,  "CHIKUCHIKU@"
-	db PONYTA,     SEEL,      TRADE_DIALOGSET_CASUAL, "SAILOR@@@@@"
-	db SPEAROW,    FARFETCHD, TRADE_DIALOGSET_HAPPY,  "DUX@@@@@@@@"
-	db SLOWBRO,    LICKITUNG, TRADE_DIALOGSET_CASUAL, "MARC@@@@@@@"
-	db POLIWHIRL,  JYNX,      TRADE_DIALOGSET_POLITE, "LOLA@@@@@@@"
-	db RAICHU,     ELECTRODE, TRADE_DIALOGSET_POLITE, "DORIS@@@@@@"
-	db VENONAT,    TANGELA,   TRADE_DIALOGSET_HAPPY,  "CRINKLES@@@"
-	db NIDORAN_M,  NIDORAN_F, TRADE_DIALOGSET_HAPPY,  "SPOT@@@@@@@"
+	; The two instances of TRADE_DIALOGSET_EVOLUTION are a leftover
+	; from the Japanese Blue trades, which used species that evolve.
+	; Japanese Red and Green used TRADE_DIALOGSET_CASUAL, and had
+	; the same species as English Red and Blue.
+	db NIDORINO,   NIDORINA,  TRADE_DIALOGSET_CASUAL,    "TERRY@@@@@@"
+	db ABRA,       MR_MIME,   TRADE_DIALOGSET_CASUAL,    "MARCEL@@@@@"
+	db BUTTERFREE, BEEDRILL,  TRADE_DIALOGSET_HAPPY,     "CHIKUCHIKU@" ; unused
+	db PONYTA,     SEEL,      TRADE_DIALOGSET_CASUAL,    "SAILOR@@@@@"
+	db SPEAROW,    FARFETCHD, TRADE_DIALOGSET_HAPPY,     "DUX@@@@@@@@"
+	db SLOWBRO,    LICKITUNG, TRADE_DIALOGSET_CASUAL,    "MARC@@@@@@@"
+	db POLIWHIRL,  JYNX,      TRADE_DIALOGSET_EVOLUTION, "LOLA@@@@@@@"
+	db RAICHU,     ELECTRODE, TRADE_DIALOGSET_EVOLUTION, "DORIS@@@@@@"
+	db VENONAT,    TANGELA,   TRADE_DIALOGSET_HAPPY,     "CRINKLES@@@"
+	db NIDORAN_M,  NIDORAN_F, TRADE_DIALOGSET_HAPPY,     "SPOT@@@@@@@"
 	assert_table_length NUM_NPC_TRADES