diff --git a/src/newgrf_townname.h b/src/newgrf_townname.h
--- a/src/newgrf_townname.h
+++ b/src/newgrf_townname.h
@@ -17,29 +17,31 @@
 #include "strings_type.h"
 
 struct NamePart {
-	byte prob;     ///< The relative probability of the following name to appear in the bottom 7 bits.
-	union {
-		char *text;    ///< If probability bit 7 is clear
-		byte id;       ///< If probability bit 7 is set
-	} data;
+	std::string text; ///< If probability bit 7 is clear
+	byte id;          ///< If probability bit 7 is set
+	byte prob;        ///< The relative probability of the following name to appear in the bottom 7 bits.
 };
 
 struct NamePartList {
-	byte partcount;
-	byte bitstart;
-	byte bitcount;
-	uint16 maxprob;
-	NamePart *parts;
+	byte bitstart;  ///< Start of random seed bits to use.
+	byte bitcount;  ///< Number of bits of random seed to use.
+	uint16 maxprob; ///< Total probability of all parts.
+	std::vector<NamePart> parts; ///< List of parts to choose from.
+};
+
+struct TownNameStyle {
+	StringID name; ///< String ID of this town name style.
+	byte id;       ///< Index within partlist for this town name style.
+
+	TownNameStyle(StringID name, byte id) : name(name), id(id) { }
 };
 
 struct GRFTownName {
-	uint32 grfid;
-	byte nb_gen;
-	byte id[128];
-	StringID name[128];
-	byte nbparts[128];
-	NamePartList *partlist[128];
-	GRFTownName *next;
+	static const uint MAX_LISTS = 128; ///< Maximum number of town name lists that can be defined per GRF.
+
+	uint32 grfid;                                   ///< GRF ID of NewGRF.
+	std::vector<TownNameStyle> styles;              ///< Style names defined by the Town Name NewGRF.
+	std::vector<NamePartList> partlists[MAX_LISTS]; ///< Lists of town name parts.
 };
 
 GRFTownName *AddGRFTownName(uint32 grfid);
@@ -47,9 +49,9 @@ GRFTownName *GetGRFTownName(uint32 grfid
 void DelGRFTownName(uint32 grfid);
 void CleanUpGRFTownNames();
 char *GRFTownNameGenerate(char *buf, uint32 grfid, uint16 gen, uint32 seed, const char *last);
-uint32 GetGRFTownNameId(int gen);
-uint16 GetGRFTownNameType(int gen);
-StringID GetGRFTownNameName(uint gen);
+uint32 GetGRFTownNameId(uint16 gen);
+uint16 GetGRFTownNameType(uint16 gen);
+StringID GetGRFTownNameName(uint16 gen);
 
 const std::vector<StringID>& GetGRFTownNameList();