diff --git a/src/command.cpp b/src/command.cpp
index 96f67ca44d..c9e744af3b 100644
--- a/src/command.cpp
+++ b/src/command.cpp
@@ -12,6 +12,7 @@
 #include "error.h"
 #include "gui.h"
 #include "command_func.h"
+#include "command_aux.h"
 #include "network/network_type.h"
 #include "network/network.h"
 #include "genworld.h"
@@ -565,7 +566,7 @@ enum CommandLogEntryFlag : uint16 {
 	CLEF_ESTIMATE_ONLY       =  0x08, ///< estimate only
 	CLEF_ONLY_SENDING        =  0x10, ///< only sending
 	CLEF_MY_CMD              =  0x20, ///< locally generated command
-	CLEF_BINARY              =  0x40, ///< binary_length is > 0
+	CLEF_AUX_DATA            =  0x40, ///< have auxiliary data
 	CLEF_SCRIPT              =  0x80, ///< command run by AI/game script
 	CLEF_TWICE               = 0x100, ///< command logged twice (only sending and execution)
 	CLEF_RANDOM              = 0x200, ///< command changed random seed
@@ -648,7 +649,7 @@ static void DumpSubCommandLog(char *&buffer, const char *last, const CommandLog
 		}
 		buffer += seprintf(buffer, last, " | %c%c%c%c%c%c%c%c%c%c%c | ",
 				fc(CLEF_ORDER_BACKUP, 'o'), fc(CLEF_RANDOM, 'r'), fc(CLEF_TWICE, '2'),
-				fc(CLEF_SCRIPT, 'a'), fc(CLEF_BINARY, 'b'), fc(CLEF_MY_CMD, 'm'), fc(CLEF_ONLY_SENDING, 's'),
+				fc(CLEF_SCRIPT, 'a'), fc(CLEF_AUX_DATA, 'b'), fc(CLEF_MY_CMD, 'm'), fc(CLEF_ONLY_SENDING, 's'),
 				fc(CLEF_ESTIMATE_ONLY, 'e'), fc(CLEF_TEXT, 't'), fc(CLEF_GENERATING_WORLD, 'g'), fc(CLEF_CMD_FAILED, 'f'));
 		buffer += seprintf(buffer, last, " %7d x %7d, p1: 0x%08X, p2: 0x%08X, ",
 				TileX(entry.tile), TileY(entry.tile), entry.p1, entry.p2);
@@ -756,17 +757,15 @@ bool IsCommandAllowedWhilePaused(uint32 cmd)
 static int _docommand_recursive = 0;
 
 struct cmd_text_info_dumper {
-	const char *CommandTextInfo(const char *text, uint32 binary_length)
+	const char *CommandTextInfo(const char *text, const CommandAuxiliaryBase *aux_data)
 	{
 		char *b = this->buffer;
 		const char *last = lastof(this->buffer);
 		if (text) {
-			b += seprintf(b, last, ", text");
+			b += seprintf(b, last, ", text: length: %u", (uint) strlen(text));
 		}
-		if (binary_length) {
-			b += seprintf(b, last, ", bin length: %u", binary_length);
-		} else if (text) {
-			b += seprintf(b, last, ", str length: %u", (uint) strlen(text));
+		if (aux_data) {
+			b += seprintf(b, last, ", aux data");
 		}
 		return this->buffer;
 	}
@@ -789,10 +788,10 @@ private:
  * @see CommandProc
  * @return the cost
  */
-CommandCost DoCommandEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, DoCommandFlag flags, uint32 cmd, const char *text, uint32 binary_length)
+CommandCost DoCommandEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, DoCommandFlag flags, uint32 cmd, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	SCOPE_INFO_FMT([=], "DoCommand: tile: %X (%d x %d), p1: 0x%X, p2: 0x%X, p3: " OTTD_PRINTFHEX64 ", flags: 0x%X, company: %s, cmd: 0x%X (%s)%s",
-			tile, TileX(tile), TileY(tile), p1, p2, p3, flags, scope_dumper().CompanyInfo(_current_company), cmd, GetCommandName(cmd), cmd_text_info_dumper().CommandTextInfo(text, binary_length));
+			tile, TileX(tile), TileY(tile), p1, p2, p3, flags, scope_dumper().CompanyInfo(_current_company), cmd, GetCommandName(cmd), cmd_text_info_dumper().CommandTextInfo(text, aux_data));
 
 	CommandCost res;
 
@@ -808,7 +807,7 @@ CommandCost DoCommandEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, DoComma
 	if (_docommand_recursive == 1 || !(flags & DC_EXEC) ) {
 		if (_docommand_recursive == 1) _cleared_object_areas.clear();
 		SetTownRatingTestMode(true);
-		res = command.Execute(tile, flags & ~DC_EXEC, p1, p2, p3, text, binary_length);
+		res = command.Execute(tile, flags & ~DC_EXEC, p1, p2, p3, text, aux_data);
 		SetTownRatingTestMode(false);
 		if (res.Failed()) {
 			goto error;
@@ -830,7 +829,7 @@ CommandCost DoCommandEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, DoComma
 	/* Execute the command here. All cost-relevant functions set the expenses type
 	 * themselves to the cost object at some point */
 	if (_docommand_recursive == 1) _cleared_object_areas.clear();
-	res = command.Execute(tile, flags, p1, p2, p3, text, binary_length);
+	res = command.Execute(tile, flags, p1, p2, p3, text, aux_data);
 	if (res.Failed()) {
 error:
 		_docommand_recursive--;
@@ -909,10 +908,10 @@ static void AppendCommandLogEntry(const CommandCost &res, TileIndex tile, uint32
  * @param binary_length The length of binary data in text
  * @return \c true if the command succeeded, else \c false.
  */
-bool DoCommandPEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, uint32 binary_length, bool my_cmd)
+bool DoCommandPEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, const CommandAuxiliaryBase *aux_data, bool my_cmd)
 {
 	SCOPE_INFO_FMT([=], "DoCommandP: tile: %X (%d x %d), p1: 0x%X, p2: 0x%X, p3: 0x" OTTD_PRINTFHEX64 ", company: %s, cmd: 0x%X (%s), my_cmd: %d%s",
-			tile, TileX(tile), TileY(tile), p1, p2, p3, scope_dumper().CompanyInfo(_current_company), cmd, GetCommandName(cmd), my_cmd, cmd_text_info_dumper().CommandTextInfo(text, binary_length));
+			tile, TileX(tile), TileY(tile), p1, p2, p3, scope_dumper().CompanyInfo(_current_company), cmd, GetCommandName(cmd), my_cmd, cmd_text_info_dumper().CommandTextInfo(text, aux_data));
 
 	/* Cost estimation is generally only done when the
 	 * local user presses shift while doing something.
@@ -945,15 +944,15 @@ bool DoCommandPEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, C
 	GameRandomSeedChecker random_state;
 	uint order_backup_update_counter = OrderBackup::GetUpdateCounter();
 
-	CommandCost res = DoCommandPInternal(tile, p1, p2, p3, cmd, callback, text, my_cmd, estimate_only, binary_length);
+	CommandCost res = DoCommandPInternal(tile, p1, p2, p3, cmd, callback, text, my_cmd, estimate_only, aux_data);
 
 	CommandLogEntryFlag log_flags;
 	log_flags = CLEF_NONE;
-	if (binary_length == 0 && !StrEmpty(text)) log_flags |= CLEF_TEXT;
+	if (!StrEmpty(text)) log_flags |= CLEF_TEXT;
 	if (estimate_only) log_flags |= CLEF_ESTIMATE_ONLY;
 	if (only_sending) log_flags |= CLEF_ONLY_SENDING;
 	if (my_cmd) log_flags |= CLEF_MY_CMD;
-	if (binary_length > 0) log_flags |= CLEF_BINARY;
+	if (aux_data != nullptr) log_flags |= CLEF_AUX_DATA;
 	if (!random_state.Check()) log_flags |= CLEF_RANDOM;
 	if (order_backup_update_counter != OrderBackup::GetUpdateCounter()) log_flags |= CLEF_ORDER_BACKUP;
 	AppendCommandLogEntry(res, tile, p1, p2, p3, cmd, log_flags, text);
@@ -988,20 +987,20 @@ bool DoCommandPEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, C
 	return res.Succeeded();
 }
 
-CommandCost DoCommandPScript(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, bool my_cmd, bool estimate_only, uint32 binary_length)
+CommandCost DoCommandPScript(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, bool my_cmd, bool estimate_only, const CommandAuxiliaryBase *aux_data)
 {
 	GameRandomSeedChecker random_state;
 	uint order_backup_update_counter = OrderBackup::GetUpdateCounter();
 
-	CommandCost res = DoCommandPInternal(tile, p1, p2, p3, cmd, callback, text, my_cmd, estimate_only, binary_length);
+	CommandCost res = DoCommandPInternal(tile, p1, p2, p3, cmd, callback, text, my_cmd, estimate_only, aux_data);
 
 	CommandLogEntryFlag log_flags;
 	log_flags = CLEF_SCRIPT;
-	if (binary_length == 0 && !StrEmpty(text)) log_flags |= CLEF_TEXT;
+	if (!StrEmpty(text)) log_flags |= CLEF_TEXT;
 	if (estimate_only) log_flags |= CLEF_ESTIMATE_ONLY;
 	if (_networking && !(cmd & CMD_NETWORK_COMMAND)) log_flags |= CLEF_ONLY_SENDING;
 	if (my_cmd) log_flags |= CLEF_MY_CMD;
-	if (binary_length > 0) log_flags |= CLEF_BINARY;
+	if (aux_data != nullptr) log_flags |= CLEF_AUX_DATA;
 	if (!random_state.Check()) log_flags |= CLEF_RANDOM;
 	if (order_backup_update_counter != OrderBackup::GetUpdateCounter()) log_flags |= CLEF_ORDER_BACKUP;
 	AppendCommandLogEntry(res, tile, p1, p2, p3, cmd, log_flags, text);
@@ -1063,7 +1062,7 @@ void EnqueueDoCommandP(CommandContainer cmd)
  * @param estimate_only whether to give only the estimate or also execute the command
  * @return the command cost of this function.
  */
-CommandCost DoCommandPInternal(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, bool my_cmd, bool estimate_only, uint32 binary_length)
+CommandCost DoCommandPInternal(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, bool my_cmd, bool estimate_only, const CommandAuxiliaryBase *aux_data)
 {
 	/* Prevent recursion; it gives a mess over the network */
 	assert(_docommand_recursive == 0);
@@ -1113,13 +1112,13 @@ CommandCost DoCommandPInternal(TileIndex tile, uint32 p1, uint32 p2, uint64 p3,
 	_cleared_object_areas.clear();
 	SetTownRatingTestMode(true);
 	BasePersistentStorageArray::SwitchMode(PSM_ENTER_TESTMODE);
-	CommandCost res = command.Execute(tile, flags, p1, p2, p3, text, binary_length);
+	CommandCost res = command.Execute(tile, flags, p1, p2, p3, text, aux_data);
 	BasePersistentStorageArray::SwitchMode(PSM_LEAVE_TESTMODE);
 	SetTownRatingTestMode(false);
 
 	if (!random_state.Check()) {
-		std::string msg = stdstr_fmt("Random seed changed in test command: company: %02x; tile: %06x (%u x %u); p1: %08x; p2: %08x; p3: " OTTD_PRINTFHEX64PAD "; cmd: %08x; \"%s\" %X (%s)",
-				(int)_current_company, tile, TileX(tile), TileY(tile), p1, p2, p3, cmd & ~CMD_NETWORK_COMMAND, text, binary_length, GetCommandName(cmd));
+		std::string msg = stdstr_fmt("Random seed changed in test command: company: %02x; tile: %06x (%u x %u); p1: %08x; p2: %08x; p3: " OTTD_PRINTFHEX64PAD "; cmd: %08x; \"%s\"%s (%s)",
+				(int)_current_company, tile, TileX(tile), TileY(tile), p1, p2, p3, cmd & ~CMD_NETWORK_COMMAND, text, aux_data != nullptr ? ", aux data present" : "", GetCommandName(cmd));
 		DEBUG(desync, 0, "msg: date{%08x; %02x; %02x}; %s", _date, _date_fract, _tick_skip_counter, msg.c_str());
 		LogDesyncMsg(std::move(msg));
 	}
@@ -1137,8 +1136,8 @@ CommandCost DoCommandPInternal(TileIndex tile, uint32 p1, uint32 p2, uint64 p3,
 		if (!_networking || _generating_world || (cmd & CMD_NETWORK_COMMAND) != 0) {
 			/* Log the failed command as well. Just to be able to be find
 			 * causes of desyncs due to bad command test implementations. */
-			DEBUG(desync, 1, "cmdf: date{%08x; %02x; %02x}; company: %02x; tile: %06x (%u x %u); p1: %08x; p2: %08x; p3: " OTTD_PRINTFHEX64PAD "; cmd: %08x; \"%s\" %X (%s)",
-					_date, _date_fract, _tick_skip_counter, (int)_current_company, tile, TileX(tile), TileY(tile), p1, p2, p3, cmd & ~CMD_NETWORK_COMMAND, text, binary_length, GetCommandName(cmd));
+			DEBUG(desync, 1, "cmdf: date{%08x; %02x; %02x}; company: %02x; tile: %06x (%u x %u); p1: %08x; p2: %08x; p3: " OTTD_PRINTFHEX64PAD "; cmd: %08x; \"%s\"%s (%s)",
+					_date, _date_fract, _tick_skip_counter, (int)_current_company, tile, TileX(tile), TileY(tile), p1, p2, p3, cmd & ~CMD_NETWORK_COMMAND, text, aux_data != nullptr ? ", aux data present" : "", GetCommandName(cmd));
 		}
 		cur_company.Restore();
 		return_dcpi(res);
@@ -1149,7 +1148,7 @@ CommandCost DoCommandPInternal(TileIndex tile, uint32 p1, uint32 p2, uint64 p3,
 	 * send it to the command-queue and abort execution
 	 */
 	if (_networking && !_generating_world && !(cmd & CMD_NETWORK_COMMAND)) {
-		NetworkSendCommand(tile, p1, p2, p3, cmd & ~CMD_FLAGS_MASK, callback, text, _current_company, binary_length);
+		NetworkSendCommand(tile, p1, p2, p3, cmd & ~CMD_FLAGS_MASK, callback, text, _current_company, aux_data);
 		cur_company.Restore();
 
 		/* Don't return anything special here; no error, no costs.
@@ -1158,14 +1157,14 @@ CommandCost DoCommandPInternal(TileIndex tile, uint32 p1, uint32 p2, uint64 p3,
 		 * reset the storages as we've not executed the command. */
 		return_dcpi(CommandCost());
 	}
-	DEBUG(desync, 1, "cmd: date{%08x; %02x; %02x}; company: %02x; tile: %06x (%u x %u); p1: %08x; p2: %08x; p3: " OTTD_PRINTFHEX64PAD "; cmd: %08x; \"%s\" %X (%s)",
-			_date, _date_fract, _tick_skip_counter, (int)_current_company, tile, TileX(tile), TileY(tile), p1, p2, p3, cmd & ~CMD_NETWORK_COMMAND, text, binary_length, GetCommandName(cmd));
+	DEBUG(desync, 1, "cmd: date{%08x; %02x; %02x}; company: %02x; tile: %06x (%u x %u); p1: %08x; p2: %08x; p3: " OTTD_PRINTFHEX64PAD "; cmd: %08x; \"%s\"%s(%s)",
+			_date, _date_fract, _tick_skip_counter, (int)_current_company, tile, TileX(tile), TileY(tile), p1, p2, p3, cmd & ~CMD_NETWORK_COMMAND, text, aux_data != nullptr ? ", aux data present" : "", GetCommandName(cmd));
 
 	/* Actually try and execute the command. If no cost-type is given
 	 * use the construction one */
 	_cleared_object_areas.clear();
 	BasePersistentStorageArray::SwitchMode(PSM_ENTER_COMMAND);
-	CommandCost res2 = command.Execute(tile, flags | DC_EXEC, p1, p2, p3, text, binary_length);
+	CommandCost res2 = command.Execute(tile, flags | DC_EXEC, p1, p2, p3, text, aux_data);
 	BasePersistentStorageArray::SwitchMode(PSM_LEAVE_COMMAND);
 
 	if (cmd_id == CMD_COMPANY_CTRL) {
diff --git a/src/command_func.h b/src/command_func.h
index fd0446df00..e1d3b400dc 100644
--- a/src/command_func.h
+++ b/src/command_func.h
@@ -32,7 +32,7 @@ static const CommandCost CMD_ERROR = CommandCost(INVALID_STRING_ID);
  */
 #define return_cmd_error(errcode) return CommandCost(errcode);
 
-CommandCost DoCommandEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, DoCommandFlag flags, uint32 cmd, const char *text = nullptr, uint32 binary_length = 0);
+CommandCost DoCommandEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, DoCommandFlag flags, uint32 cmd, const char *text = nullptr, const CommandAuxiliaryBase *aux_data = nullptr);
 
 inline CommandCost DoCommand(TileIndex tile, uint32 p1, uint32 p2, DoCommandFlag flags, uint32 cmd, const char *text = nullptr)
 {
@@ -40,10 +40,10 @@ inline CommandCost DoCommand(TileIndex tile, uint32 p1, uint32 p2, DoCommandFlag
 }
 inline CommandCost DoCommand(const CommandContainer *container, DoCommandFlag flags)
 {
-	return DoCommandEx(container->tile, container->p1, container->p2, container->p3, flags, container->cmd & CMD_ID_MASK, container->text.c_str(), container->binary_length);
+	return DoCommandEx(container->tile, container->p1, container->p2, container->p3, flags, container->cmd & CMD_ID_MASK, container->text.c_str(), container->aux_data.get());
 }
 
-bool DoCommandPEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, uint32 binary_length, bool my_cmd = true);
+bool DoCommandPEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, const CommandAuxiliaryBase *aux_data, bool my_cmd = true);
 
 inline bool DoCommandP(TileIndex tile, uint32 p1, uint32 p2, uint32 cmd, CommandCallback *callback = nullptr, const char *text = nullptr, bool my_cmd = true)
 {
@@ -52,13 +52,13 @@ inline bool DoCommandP(TileIndex tile, uint32 p1, uint32 p2, uint32 cmd, Command
 
 inline bool DoCommandP(const CommandContainer *container, bool my_cmd = true)
 {
-	return DoCommandPEx(container->tile, container->p1, container->p2, container->p3, container->cmd, container->callback, container->text.c_str(), container->binary_length, my_cmd);
+	return DoCommandPEx(container->tile, container->p1, container->p2, container->p3, container->cmd, container->callback, container->text.c_str(), container->aux_data.get(), my_cmd);
 }
 
-CommandCost DoCommandPScript(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, bool my_cmd, bool estimate_only, uint32 binary_length);
-CommandCost DoCommandPInternal(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, bool my_cmd, bool estimate_only, uint32 binary_length);
+CommandCost DoCommandPScript(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, bool my_cmd, bool estimate_only, const CommandAuxiliaryBase *aux_data);
+CommandCost DoCommandPInternal(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, bool my_cmd, bool estimate_only, const CommandAuxiliaryBase *aux_data);
 
-void NetworkSendCommand(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, CompanyID company, uint32 binary_length);
+void NetworkSendCommand(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, CompanyID company, const CommandAuxiliaryBase *aux_data);
 
 extern Money _additional_cash_required;
 
diff --git a/src/command_type.h b/src/command_type.h
index 0247b23b33..a37af9ec72 100644
--- a/src/command_type.h
+++ b/src/command_type.h
@@ -621,6 +621,8 @@ enum CommandPauseLevel {
 	CMDPL_ALL_ACTIONS,     ///< All actions may be executed.
 };
 
+struct CommandAuxiliaryBase;
+
 /**
  * Defines the callback type for all command handler functions.
  *
@@ -640,7 +642,7 @@ enum CommandPauseLevel {
  * @return The CommandCost of the command, which can be succeeded or failed.
  */
 typedef CommandCost CommandProc(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text);
-typedef CommandCost CommandProcEx(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length);
+typedef CommandCost CommandProcEx(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data);
 
 /**
  * Define a command with the flags which belongs to it.
@@ -662,9 +664,9 @@ struct Command {
 	Command(CommandProcEx *procex, const char *name, CommandFlags flags, CommandType type)
 			: procex(procex), name(name), flags(flags | CMD_PROCEX), type(type) {}
 
-	inline CommandCost Execute(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length) const {
+	inline CommandCost Execute(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data) const {
 		if (this->flags & CMD_PROCEX) {
-			return this->procex(tile, flags, p1, p2, p3, text, binary_length);
+			return this->procex(tile, flags, p1, p2, p3, text, aux_data);
 		} else {
 			return this->proc(tile, flags, p1, p2, text);
 		}
@@ -733,13 +735,13 @@ struct CommandContainer {
 	uint32 cmd;                      ///< command being executed.
 	uint64 p3;                       ///< parameter p3. (here for alignment)
 	CommandCallback *callback;       ///< any callback function executed upon successful completion of the command.
-	uint32 binary_length;            ///< in case text contains binary data, this describes its length.
 	std::string text;                ///< possible text sent for name changes etc.
+	CommandAuxiliaryPtr aux_data;    ///< Auxiliary command data
 };
 
 inline CommandContainer NewCommandContainerBasic(TileIndex tile, uint32 p1, uint32 p2, uint32 cmd, CommandCallback *callback = nullptr)
 {
-	return { tile, p1, p2, cmd, 0, callback, 0, {} };
+	return { tile, p1, p2, cmd, 0, callback, {}, nullptr };
 }
 
 #endif /* COMMAND_TYPE_H */
diff --git a/src/company_cmd.cpp b/src/company_cmd.cpp
index ff4c26ce37..68388aec62 100644
--- a/src/company_cmd.cpp
+++ b/src/company_cmd.cpp
@@ -922,7 +922,7 @@ CommandCost CmdCompanyCtrl(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 
 				/* In network games, we need to try setting the company manager face here to sync it to all clients.
 				 * If a favorite company manager face is selected, choose it. Otherwise, use a random face. */
-				if (_company_manager_face != 0) NetworkSendCommand(0, 0, _company_manager_face, 0, CMD_SET_COMPANY_MANAGER_FACE, nullptr, nullptr, _local_company, 0);
+				if (_company_manager_face != 0) NetworkSendCommand(0, 0, _company_manager_face, 0, CMD_SET_COMPANY_MANAGER_FACE, nullptr, nullptr, _local_company, nullptr);
 
 				/* Now that we have a new company, broadcast our company settings to
 				 * all clients so everything is in sync */
diff --git a/src/league_cmd.cpp b/src/league_cmd.cpp
index b201025e8e..e74a1ac8de 100644
--- a/src/league_cmd.cpp
+++ b/src/league_cmd.cpp
@@ -190,7 +190,7 @@ CommandCost CmdCreateLeagueTable(TileIndex tile, DoCommandFlag flags, uint32 p1,
 	return res;
 }
 
-CommandCost CmdCreateLeagueTableElement(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdCreateLeagueTableElement(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	std::string text_str, score;
 	text = StrConsumeToSeparator(text_str, text);
@@ -227,7 +227,7 @@ CommandCost CmdUpdateLeagueTableElementData(TileIndex tile, DoCommandFlag flags,
 	return CmdUpdateLeagueTableElementData(flags, element, company, text, link_type, link_target);
 }
 
-CommandCost CmdUpdateLeagueTableElementScore(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdUpdateLeagueTableElementScore(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	return CmdUpdateLeagueTableElementScore(flags, p1, p3, text);
 }
diff --git a/src/network/core/packet.cpp b/src/network/core/packet.cpp
index fd252ab2d5..01803948b0 100644
--- a/src/network/core/packet.cpp
+++ b/src/network/core/packet.cpp
@@ -85,6 +85,13 @@ bool Packet::CanWriteToPacket(size_t bytes_to_write)
 	return this->Size() + bytes_to_write <= this->limit;
 }
 
+void Packet::WriteAtOffset_uint16(size_t offset, uint16 data)
+{
+	assert(offset + 1 < this->buffer.size());
+	this->buffer[offset]     = GB(data, 0, 8);
+	this->buffer[offset + 1] = GB(data, 8, 8);
+}
+
 
 
 /*
diff --git a/src/network/core/packet.h b/src/network/core/packet.h
index 8f1bbc2cb1..5b8cca594c 100644
--- a/src/network/core/packet.h
+++ b/src/network/core/packet.h
@@ -72,7 +72,9 @@ public:
 	PacketSize &GetDeserialisationPosition() { return this->pos; }
 	bool CanDeserialiseBytes(size_t bytes_to_read, bool raise_error) { return this->CanReadFromPacket(bytes_to_read, raise_error); }
 
-	bool   CanWriteToPacket(size_t bytes_to_write);
+	bool CanWriteToPacket(size_t bytes_to_write);
+
+	void WriteAtOffset_uint16(size_t offset, uint16);
 
 	/* Reading/receiving of packets */
 	size_t ReadRawPacketSize() const;
diff --git a/src/network/network.cpp b/src/network/network.cpp
index 12acbb375d..33a2ac962e 100644
--- a/src/network/network.cpp
+++ b/src/network/network.cpp
@@ -1120,7 +1120,7 @@ void NetworkGameLoop()
 		while (f != nullptr && !feof(f)) {
 			if (_date == next_date && _date_fract == next_date_fract) {
 				if (cp != nullptr) {
-					NetworkSendCommand(cp->tile, cp->p1, cp->p2, cp->p3, cp->cmd & ~CMD_FLAGS_MASK, nullptr, cp->text.c_str(), cp->company, cp->binary_length);
+					NetworkSendCommand(cp->tile, cp->p1, cp->p2, cp->p3, cp->cmd & ~CMD_FLAGS_MASK, nullptr, cp->text.c_str(), cp->company, cp->aux_data);
 					DEBUG(net, 0, "injecting: date{%08x; %02x; %02x}; %02x; %06x; %08x; %08x; " OTTD_PRINTFHEX64PAD " %08x; \"%s\" (%x) (%s)", _date, _date_fract, _tick_skip_counter, (int)_current_company, cp->tile, cp->p1, cp->p2, cp->p3, cp->cmd, cp->text.c_str(), cp->binary_length, GetCommandName(cp->cmd));
 					cp.reset();
 				}
@@ -1167,7 +1167,7 @@ void NetworkGameLoop()
 				 * string misses because in 99% of the time it's not used. */
 				assert(ret == 10 || ret == 9);
 				cp->company = (CompanyID)company;
-				cp->binary_length = 0;
+				cp->aux_data = nullptr;
 			} else if (strncmp(p, "join: ", 6) == 0) {
 				/* Manually insert a pause when joining; this way the client can join at the exact right time. */
 				int ret = sscanf(p + 6, "date{%x; %x; %x}", &next_date, &next_date_fract, &next_tick_skip_counter);
@@ -1181,7 +1181,7 @@ void NetworkGameLoop()
 				cp->p2 = 1;
 				cp->p3 = 0;
 				cp->callback = nullptr;
-				cp->binary_length = 0;
+				cp->aux_data = nullptr;
 				_ddc_fastforward = false;
 			} else if (strncmp(p, "sync: ", 6) == 0) {
 				int ret = sscanf(p + 6, "date{%x; %x; %x}; %x; %x", &next_date, &next_date_fract, &next_tick_skip_counter, &sync_state[0], &sync_state[1]);
diff --git a/src/network/network_client.cpp b/src/network/network_client.cpp
index e5439b7c46..b58c461813 100644
--- a/src/network/network_client.cpp
+++ b/src/network/network_client.cpp
@@ -1002,7 +1002,7 @@ NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_MAP_DONE(Packet
 			 * the server will give us a client-id and let us in */
 			_network_join_status = NETWORK_JOIN_STATUS_REGISTERING;
 			ShowJoinStatusWindow();
-			NetworkSendCommand(0, CCA_NEW, 0, 0, CMD_COMPANY_CTRL, nullptr, nullptr, _local_company, 0);
+			NetworkSendCommand(0, CCA_NEW, 0, 0, CMD_COMPANY_CTRL, nullptr, nullptr, _local_company, nullptr);
 		}
 	} else {
 		/* take control over an existing company */
diff --git a/src/network/network_command.cpp b/src/network/network_command.cpp
index 51fc9619fc..fa47cc4b0f 100644
--- a/src/network/network_command.cpp
+++ b/src/network/network_command.cpp
@@ -12,6 +12,7 @@
 #include "network_client.h"
 #include "network_server.h"
 #include "../command_func.h"
+#include "../command_aux.h"
 #include "../company_func.h"
 #include "../settings_type.h"
 
@@ -143,9 +144,9 @@ static CommandQueue _local_execution_queue;
  * @param callback A callback function to call after the command is finished
  * @param text The text to pass
  * @param company The company that wants to send the command
- * @param binary_length The quantity of binary data in text
+ * @param aux_data Auxiliary command data
  */
-void NetworkSendCommand(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, CompanyID company, uint32 binary_length)
+void NetworkSendCommand(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32 cmd, CommandCallback *callback, const char *text, CompanyID company, const CommandAuxiliaryBase *aux_data)
 {
 	assert((cmd & CMD_FLAGS_MASK) == 0);
 
@@ -157,16 +158,12 @@ void NetworkSendCommand(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint32
 	c.p3       = p3;
 	c.cmd      = cmd;
 	c.callback = callback;
+	if (aux_data != nullptr) c.aux_data.reset(aux_data->Clone());
 
-	c.binary_length = binary_length;
-	if (binary_length == 0) {
-		if (text != nullptr) {
-			c.text.assign(text);
-		} else {
-			c.text.clear();
-		}
+	if (text != nullptr) {
+		c.text.assign(text);
 	} else {
-		c.text.assign(text, binary_length);
+		c.text.clear();
 	}
 
 	if (_network_server) {
@@ -328,21 +325,24 @@ const char *NetworkGameSocketHandler::ReceiveCommand(Packet *p, CommandPacket *c
 	cp->p2      = p->Recv_uint32();
 	cp->p3      = p->Recv_uint64();
 	cp->tile    = p->Recv_uint32();
-	cp->binary_length = p->Recv_uint32();
-	if (cp->binary_length == 0) {
-		StringValidationSettings settings = (!_network_server && GetCommandFlags(cp->cmd) & CMD_STR_CTRL) != 0 ? SVS_ALLOW_CONTROL_CODE | SVS_REPLACE_WITH_QUESTION_MARK : SVS_REPLACE_WITH_QUESTION_MARK;
-		if (GetCommandFlags(cp->cmd) & CMD_STR_SEP) settings |= SVS_ALLOW_SEPARATOR_CODE;
-		p->Recv_string(cp->text, settings);
-	} else {
-		if (!p->CanReadFromPacket(cp->binary_length + /* callback index */ 1)) return "invalid binary data length";
-		if (cp->binary_length > MAX_CMD_TEXT_LENGTH) return "over-size binary data length";
-		p->Recv_binary(cp->text, cp->binary_length);
-	}
+
+	StringValidationSettings settings = (!_network_server && GetCommandFlags(cp->cmd) & CMD_STR_CTRL) != 0 ? SVS_ALLOW_CONTROL_CODE | SVS_REPLACE_WITH_QUESTION_MARK : SVS_REPLACE_WITH_QUESTION_MARK;
+	if (GetCommandFlags(cp->cmd) & CMD_STR_SEP) settings |= SVS_ALLOW_SEPARATOR_CODE;
+	p->Recv_string(cp->text, settings);
 
 	byte callback = p->Recv_uint8();
 	if (callback >= lengthof(_callback_table))  return "invalid callback";
 
 	cp->callback = _callback_table[callback];
+
+	uint16 aux_data_size = p->Recv_uint16();
+	if (aux_data_size > 0 && p->CanReadFromPacket(aux_data_size, true)) {
+		CommandAuxiliarySerialised *aux_data = new CommandAuxiliarySerialised();
+		cp->aux_data.reset(aux_data);
+		aux_data->serialised_data.resize(aux_data_size);
+		p->Recv_binary((char *)(aux_data->serialised_data.data()), aux_data_size);
+	}
+
 	return nullptr;
 }
 
@@ -359,13 +359,7 @@ void NetworkGameSocketHandler::SendCommand(Packet *p, const CommandPacket *cp)
 	p->Send_uint32(cp->p2);
 	p->Send_uint64(cp->p3);
 	p->Send_uint32(cp->tile);
-	p->Send_uint32(cp->binary_length);
-	if (cp->binary_length == 0) {
-		p->Send_string(cp->text.c_str());
-	} else {
-		assert(cp->text.size() >= cp->binary_length);
-		p->Send_binary(cp->text.c_str(), cp->binary_length);
-	}
+	p->Send_string(cp->text.c_str());
 
 	byte callback = 0;
 	while (callback < lengthof(_callback_table) && _callback_table[callback] != cp->callback) {
@@ -377,4 +371,12 @@ void NetworkGameSocketHandler::SendCommand(Packet *p, const CommandPacket *cp)
 		callback = 0; // _callback_table[0] == nullptr
 	}
 	p->Send_uint8 (callback);
+
+	size_t aux_data_size_pos = p->Size();
+	p->Send_uint16(0);
+	if (cp->aux_data != nullptr) {
+		CommandSerialisationBuffer serialiser(p->GetSerialisationBuffer(), p->GetSerialisationLimit());
+		cp->aux_data->Serialise(serialiser);
+		p->WriteAtOffset_uint16(aux_data_size_pos, (uint16)(p->Size() - aux_data_size_pos - 2));
+	}
 }
diff --git a/src/network/network_gui.cpp b/src/network/network_gui.cpp
index 0ca11bd4d6..905573ee83 100644
--- a/src/network/network_gui.cpp
+++ b/src/network/network_gui.cpp
@@ -1563,7 +1563,7 @@ private:
 		if (_network_server) {
 			DoCommandP(0, CCA_NEW, _network_own_client_id, CMD_COMPANY_CTRL);
 		} else {
-			NetworkSendCommand(0, CCA_NEW, 0, 0, CMD_COMPANY_CTRL, nullptr, nullptr, _local_company, 0);
+			NetworkSendCommand(0, CCA_NEW, 0, 0, CMD_COMPANY_CTRL, nullptr, nullptr, _local_company, nullptr);
 		}
 	}
 
diff --git a/src/network/network_server.cpp b/src/network/network_server.cpp
index 87d12a8143..207c52bec9 100644
--- a/src/network/network_server.cpp
+++ b/src/network/network_server.cpp
@@ -1211,7 +1211,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_ERROR(Packet *p
 		_settings_client.network.sync_freq = std::min<uint16>(_settings_client.network.sync_freq, 16);
 
 		// have the server and all clients run some sanity checks
-		NetworkSendCommand(0, 0, 0, 0, CMD_DESYNC_CHECK, nullptr, nullptr, _local_company, 0);
+		NetworkSendCommand(0, 0, 0, 0, CMD_DESYNC_CHECK, nullptr, nullptr, _local_company, nullptr);
 
 		SendPacketsState send_state = this->SendPackets(true);
 		if (send_state != SPS_CLOSED) {
@@ -2301,7 +2301,7 @@ void NetworkServerNewCompany(const Company *c, NetworkClientInfo *ci)
 		/* ci is nullptr when replaying, or for AIs. In neither case there is a client. */
 		ci->client_playas = c->index;
 		NetworkUpdateClientInfo(ci->client_id);
-		NetworkSendCommand(0, 0, 0, 0, CMD_RENAME_PRESIDENT, nullptr, ci->client_name.c_str(), c->index, 0);
+		NetworkSendCommand(0, 0, 0, 0, CMD_RENAME_PRESIDENT, nullptr, ci->client_name.c_str(), c->index, nullptr);
 	}
 
 	/* Announce new company on network. */
diff --git a/src/order_cmd.cpp b/src/order_cmd.cpp
index cefb7411a7..5cffd99a6c 100644
--- a/src/order_cmd.cpp
+++ b/src/order_cmd.cpp
@@ -966,7 +966,7 @@ uint GetOrderDistance(const Order *prev, const Order *cur, const Vehicle *v, int
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdInsertOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdInsertOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	VehicleID veh          = GB(p1,  0, 20);
 	VehicleOrderID sel_ord = GB(p2,  0, 16);
@@ -1758,7 +1758,7 @@ CommandCost CmdReverseOrderList(TileIndex tile, DoCommandFlag flags, uint32 p1,
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdModifyOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdModifyOrder(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	VehicleOrderID sel_ord = GB(p3,  0, 16);
 	VehicleID veh          = GB(p1,  0, 20);
diff --git a/src/plans.cpp b/src/plans.cpp
index 1477825e24..9f75fce3df 100644
--- a/src/plans.cpp
+++ b/src/plans.cpp
@@ -47,3 +47,19 @@ void PlanLine::UpdateVisualExtents()
 	this->viewport_extents = { (int)(min_x * TILE_SIZE * 2 * ZOOM_LVL_BASE), (int)(min_y * TILE_SIZE * ZOOM_LVL_BASE),
 			(int)((max_x + 1) * TILE_SIZE * 2 * ZOOM_LVL_BASE), (int)((max_y + 1) * TILE_SIZE * ZOOM_LVL_BASE) };
 }
+
+bool Plan::ValidateNewLine()
+{
+	extern bool AddPlanLine(PlanID plan, TileVector tiles);
+
+	bool ret = false;
+	if (this->temp_line->tiles.size() > 1) {
+		this->temp_line->MarkDirty();
+		this->last_tile = this->temp_line->tiles.back();
+		this->SetVisibility(true, false);
+		TileVector tiles = std::move(this->temp_line->tiles);
+		this->temp_line->Clear();
+		ret = AddPlanLine(this->index, std::move(tiles));
+	}
+	return ret;
+}
diff --git a/src/plans_base.h b/src/plans_base.h
index 00f7cc0a16..1e66bb366c 100644
--- a/src/plans_base.h
+++ b/src/plans_base.h
@@ -18,7 +18,6 @@
 #include "map_func.h"
 #include "date_func.h"
 #include "viewport_func.h"
-#include "core/endian_func.hpp"
 #include <string>
 #include <vector>
 
@@ -111,30 +110,6 @@ struct PlanLine {
 		}
 	}
 
-	TileIndex *Export(uint *buffer_length)
-	{
-		const uint cnt = (uint) this->tiles.size();
-		const uint datalen = sizeof(TileIndex) * cnt;
-		TileIndex *buffer = (TileIndex *) malloc(datalen);
-		if (buffer) {
-			for (uint i = 0; i < cnt; i++) {
-				buffer[i] = TO_LE32(this->tiles[i]);
-			}
-			if (buffer_length) *buffer_length = datalen;
-		}
-		return buffer;
-	}
-
-	bool Import(const TileIndex* data, const uint data_length)
-	{
-		for (uint i = data_length; i != 0; i--, data++) {
-			TileIndex t = FROM_LE32(*data);
-			if (t >= MapSize()) return false;
-			this->tiles.push_back(t);
-		}
-		return true;
-	}
-
 	void AddLineToCalculateCentreTile(uint64 &x, uint64 &y, uint32 &count) const
 	{
 		for (size_t i = 0; i < this->tiles.size(); i++) {
@@ -226,24 +201,7 @@ struct Plan : PlanPool::PoolItem<&_plan_pool> {
 		return this->temp_line->AppendTile(tile);
 	}
 
-	bool ValidateNewLine()
-	{
-		bool ret = false;
-		if (this->temp_line->tiles.size() > 1) {
-			uint buffer_length = 0;
-			const TileIndex *buffer = this->temp_line->Export(&buffer_length);
-			uint tiles = (uint)this->temp_line->tiles.size();
-			this->temp_line->MarkDirty();
-			this->last_tile = this->temp_line->tiles.back();
-			this->temp_line->Clear();
-			if (buffer) {
-				this->SetVisibility(true, false);
-				ret = DoCommandPEx(0, this->index, tiles, 0, CMD_ADD_PLAN_LINE, nullptr, (const char *) buffer, buffer_length);
-				free(buffer);
-			}
-		}
-		return ret;
-	}
+	bool ValidateNewLine();
 
 	bool IsListable()
 	{
diff --git a/src/plans_cmd.cpp b/src/plans_cmd.cpp
index 7ce8efb179..7e1e7e5dd1 100644
--- a/src/plans_cmd.cpp
+++ b/src/plans_cmd.cpp
@@ -9,6 +9,7 @@
 
 #include "stdafx.h"
 #include "command_func.h"
+#include "command_aux.h"
 #include "plans_base.h"
 #include "plans_func.h"
 #include "window_func.h"
@@ -43,6 +44,36 @@ CommandCost CmdAddPlan(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2
 	return CommandCost();
 }
 
+struct PlanLineCmdData : public CommandAuxiliarySerialisable<PlanLineCmdData> {
+	TileVector tiles;
+
+	virtual void Serialise(CommandSerialisationBuffer &buffer) const override
+	{
+		buffer.Send_uint32((uint32)this->tiles.size());
+		for (TileIndex t : this->tiles) {
+			buffer.Send_uint32(t);
+		}
+	}
+
+	CommandCost Deserialise(CommandDeserialisationBuffer &buffer)
+	{
+		uint32 size = buffer.Recv_uint32();
+		if (!buffer.CanRecvBytes(size * 4)) return CMD_ERROR;
+		this->tiles.resize(size);
+		for (uint i = 0; i < size; i++) {
+			this->tiles[i] = buffer.Recv_uint32();
+		}
+		return CommandCost();
+	}
+};
+
+bool AddPlanLine(PlanID plan, TileVector tiles)
+{
+	PlanLineCmdData data;
+	data.tiles = std::move(tiles);
+	return DoCommandPEx(0, plan, 0, 0, CMD_ADD_PLAN_LINE, nullptr, nullptr, &data);
+}
+
 /**
  * Create a new line in a plan.
  * @param tile unused
@@ -50,25 +81,25 @@ CommandCost CmdAddPlan(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2
  * @param p1 plan id
  * @param p2 number of nodes
  * @param text list of tile indexes that compose the line
- * @param binary_length binary length of text
+ * @param aux_data auxiliary data
  * @return the cost of this operation or an error
  */
-CommandCost CmdAddPlanLine(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdAddPlanLine(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	Plan *p = Plan::GetIfValid(p1);
 	if (p == nullptr) return CMD_ERROR;
 	CommandCost ret = CheckOwnership(p->owner);
 	if (ret.Failed()) return ret;
-	if (p2 > (MAX_CMD_TEXT_LENGTH / sizeof(TileIndex))) return_cmd_error(STR_ERROR_TOO_MANY_NODES);
-	if (!text || binary_length != p2 * 4) return CMD_ERROR;
+
+	CommandAuxData<PlanLineCmdData> data;
+	ret = data.Load(aux_data);
+	if (ret.Failed()) return ret;
+
+	if (data->tiles.size() > (MAX_CMD_TEXT_LENGTH / sizeof(TileIndex))) return_cmd_error(STR_ERROR_TOO_MANY_NODES);
 	if (flags & DC_EXEC) {
 		PlanLine *pl = p->NewLine();
 		if (!pl) return_cmd_error(STR_ERROR_NO_MORE_SPACE_FOR_LINES);
-		if (!pl->Import((const TileIndex *) text, p2)) {
-			delete pl;
-			p->lines.pop_back();
-			return CMD_ERROR;
-		}
+		pl->tiles = std::move(data->tiles);
 		pl->UpdateVisualExtents();
 		if (p->IsListable()) {
 			pl->SetVisibility(p->visible);
diff --git a/src/schdispatch_cmd.cpp b/src/schdispatch_cmd.cpp
index 8fb216bd6d..bfb87330fc 100644
--- a/src/schdispatch_cmd.cpp
+++ b/src/schdispatch_cmd.cpp
@@ -73,7 +73,7 @@ CommandCost CmdScheduledDispatch(TileIndex tile, DoCommandFlag flags, uint32 p1,
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdScheduledDispatchAdd(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdScheduledDispatchAdd(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	VehicleID veh = GB(p1, 0, 20);
 	uint schedule_index = GB(p1, 20, 12);
@@ -185,7 +185,7 @@ CommandCost CmdScheduledDispatchSetDuration(TileIndex tile, DoCommandFlag flags,
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdScheduledDispatchSetStartDate(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdScheduledDispatchSetStartDate(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	VehicleID veh = GB(p1, 0, 20);
 	uint schedule_index = GB(p1, 20, 12);
@@ -330,7 +330,7 @@ CommandCost CmdScheduledDispatchClear(TileIndex tile, DoCommandFlag flags, uint3
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdScheduledDispatchAddNewSchedule(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdScheduledDispatchAddNewSchedule(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	VehicleID veh = GB(p1, 0, 20);
 
diff --git a/src/script/api/script_object.cpp b/src/script/api/script_object.cpp
index fefadb7bfa..fff867ed65 100644
--- a/src/script/api/script_object.cpp
+++ b/src/script/api/script_object.cpp
@@ -313,7 +313,7 @@ ScriptObject::ActiveInstance::~ActiveInstance()
 	return GetStorage()->callback_value[index];
 }
 
-/* static */ bool ScriptObject::DoCommandEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint cmd, const char *text, uint32 binary_length, Script_SuspendCallbackProc *callback)
+/* static */ bool ScriptObject::DoCommandEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint cmd, const char *text, const CommandAuxiliaryBase *aux_data, Script_SuspendCallbackProc *callback)
 {
 	if (!ScriptObject::CanSuspend()) {
 		throw Script_FatalError("You are not allowed to execute any DoCommand (even indirect) in your constructor, Save(), Load(), and any valuator.");
@@ -325,7 +325,7 @@ ScriptObject::ActiveInstance::~ActiveInstance()
 	}
 
 	std::string text_validated;
-	if (binary_length == 0 && !StrEmpty(text) && (GetCommandFlags(cmd) & CMD_STR_CTRL) == 0) {
+	if (!StrEmpty(text) && (GetCommandFlags(cmd) & CMD_STR_CTRL) == 0) {
 		/* The string must be valid, i.e. not contain special codes. Since some
 		 * can be made with GSText, make sure the control codes are removed. */
 		text_validated = text;
@@ -349,7 +349,7 @@ ScriptObject::ActiveInstance::~ActiveInstance()
 	if (!estimate_only && _networking && !_generating_world) SetLastCommand(tile, p1, p2, p3, cmd);
 
 	/* Try to perform the command. */
-	CommandCost res = ::DoCommandPScript(tile, p1, p2, p3, cmd, (_networking && !_generating_world) ? ScriptObject::GetActiveInstance()->GetDoCommandCallback() : nullptr, text, false, estimate_only, binary_length);
+	CommandCost res = ::DoCommandPScript(tile, p1, p2, p3, cmd, (_networking && !_generating_world) ? ScriptObject::GetActiveInstance()->GetDoCommandCallback() : nullptr, text, false, estimate_only, aux_data);
 
 	/* We failed; set the error and bail out */
 	if (res.Failed()) {
diff --git a/src/script/api/script_object.hpp b/src/script/api/script_object.hpp
index a5dedd267d..f0e921dcee 100644
--- a/src/script/api/script_object.hpp
+++ b/src/script/api/script_object.hpp
@@ -18,6 +18,8 @@
 #include "../script_suspend.hpp"
 #include "../squirrel.hpp"
 
+struct CommandAuxiliaryBase;
+
 /**
  * The callback function for Mode-classes.
  */
@@ -69,7 +71,7 @@ protected:
 	/**
 	 * Executes a raw DoCommand for the script.
 	 */
-	static bool DoCommandEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint cmd, const char *text = nullptr, uint32 binary_length = 0, Script_SuspendCallbackProc *callback = nullptr);
+	static bool DoCommandEx(TileIndex tile, uint32 p1, uint32 p2, uint64 p3, uint cmd, const char *text = nullptr, const CommandAuxiliaryBase *aux_data = nullptr, Script_SuspendCallbackProc *callback = nullptr);
 
 	static bool DoCommand(TileIndex tile, uint32 p1, uint32 p2, uint cmd, const char *text = nullptr, Script_SuspendCallbackProc *callback = nullptr)
 	{
diff --git a/src/settings.cpp b/src/settings.cpp
index 92f46e5d0c..4e8c08b09c 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -2647,7 +2647,7 @@ void SyncCompanySettings()
 		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to, sd->save.ext_feature_test)) continue;
 		uint32 old_value = (uint32)sd->AsIntSetting()->Read(old_object);
 		uint32 new_value = (uint32)sd->AsIntSetting()->Read(new_object);
-		if (old_value != new_value) NetworkSendCommand(0, 0, new_value, 0, CMD_CHANGE_COMPANY_SETTING, nullptr, sd->name, _local_company, 0);
+		if (old_value != new_value) NetworkSendCommand(0, 0, new_value, 0, CMD_CHANGE_COMPANY_SETTING, nullptr, sd->name, _local_company, nullptr);
 	}
 }
 
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index ebb648b544..67e1b394cb 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -2087,7 +2087,7 @@ static CommandCost FindJoiningRoadStop(StationID existing_stop, StationID statio
  * @param text Unused.
  * @return The cost of this operation or an error.
  */
-CommandCost CmdBuildRoadStop(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdBuildRoadStop(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	bool type = HasBit(p2, 0);
 	bool is_drive_through = HasBit(p2, 1);
diff --git a/src/timetable_cmd.cpp b/src/timetable_cmd.cpp
index 3e91572647..adb119b327 100644
--- a/src/timetable_cmd.cpp
+++ b/src/timetable_cmd.cpp
@@ -162,7 +162,7 @@ static void ChangeTimetable(Vehicle *v, VehicleOrderID order_number, uint32 val,
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdChangeTimetable(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdChangeTimetable(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	VehicleID veh = GB(p1, 0, 20);
 
diff --git a/src/waypoint_cmd.cpp b/src/waypoint_cmd.cpp
index 10e0a693e0..2e713b9000 100644
--- a/src/waypoint_cmd.cpp
+++ b/src/waypoint_cmd.cpp
@@ -199,7 +199,7 @@ extern CommandCost IsRailStationBridgeAboveOk(TileIndex tile, const StationSpec
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdBuildRailWaypoint(TileIndex start_tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdBuildRailWaypoint(TileIndex start_tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	/* Unpack parameters */
 	Axis axis      = Extract<Axis, 6, 1>(p1);
@@ -344,7 +344,7 @@ CommandCost CmdBuildRailWaypoint(TileIndex start_tile, DoCommandFlag flags, uint
  * @param text Unused.
  * @return The cost of this operation or an error.
  */
-CommandCost CmdBuildRoadWaypoint(TileIndex start_tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, uint32 binary_length)
+CommandCost CmdBuildRoadWaypoint(TileIndex start_tile, DoCommandFlag flags, uint32 p1, uint32 p2, uint64 p3, const char *text, const CommandAuxiliaryBase *aux_data)
 {
 	StationID station_to_join = GB(p2, 16, 16);
 	byte width     = GB(p1, 0, 8);