diff --git a/src/openrct2-ui/interface/ViewportInteraction.cpp b/src/openrct2-ui/interface/ViewportInteraction.cpp
index c524ab3eef..0a27d8104c 100644
--- a/src/openrct2-ui/interface/ViewportInteraction.cpp
+++ b/src/openrct2-ui/interface/ViewportInteraction.cpp
@@ -582,7 +582,7 @@ bool ViewportInteractionRightClick(const ScreenCoordsXY& screenCoords)
             ViewportInteractionRemoveLargeScenery(info.Element, info.Loc);
             break;
         case ViewportInteractionItem::Banner:
-            context_open_detail_window(WD_BANNER, info.Element->AsBanner()->GetIndex());
+            context_open_detail_window(WD_BANNER, info.Element->AsBanner()->GetIndex().ToUnderlying());
             break;
     }
 
@@ -669,7 +669,7 @@ static void ViewportInteractionRemoveParkWall(TileElement* tileElement, const Co
     auto* wallEntry = tileElement->AsWall()->GetEntry();
     if (wallEntry->scrolling_mode != SCROLLING_MODE_NONE)
     {
-        context_open_detail_window(WD_SIGN_SMALL, tileElement->AsWall()->GetBannerIndex());
+        context_open_detail_window(WD_SIGN_SMALL, tileElement->AsWall()->GetBannerIndex().ToUnderlying());
     }
     else
     {
@@ -690,7 +690,7 @@ static void ViewportInteractionRemoveLargeScenery(TileElement* tileElement, cons
     if (sceneryEntry->scrolling_mode != SCROLLING_MODE_NONE)
     {
         auto bannerIndex = tileElement->AsLargeScenery()->GetBannerIndex();
-        context_open_detail_window(WD_SIGN, bannerIndex);
+        context_open_detail_window(WD_SIGN, bannerIndex.ToUnderlying());
     }
     else
     {
diff --git a/src/openrct2-ui/windows/Banner.cpp b/src/openrct2-ui/windows/Banner.cpp
index bcb64c179e..7482c8be4f 100644
--- a/src/openrct2-ui/windows/Banner.cpp
+++ b/src/openrct2-ui/windows/Banner.cpp
@@ -88,9 +88,14 @@ private:
         Invalidate();
     }
 
+    BannerIndex GetBannerIndex() const
+    {
+        return BannerIndex::FromUnderlying(number);
+    }
+
     BannerElement* GetBannerElement()
     {
-        auto* banner = GetBanner(number);
+        auto* banner = GetBanner(GetBannerIndex());
         if (banner == nullptr)
         {
             return nullptr;
@@ -109,7 +114,7 @@ private:
             {
                 continue;
             }
-            if (bannerElement->GetIndex() == number)
+            if (bannerElement->GetIndex() == GetBannerIndex())
             {
                 return bannerElement;
             }
@@ -131,7 +136,7 @@ public:
     void Initialise(rct_windownumber _number)
     {
         number = _number;
-        auto* banner = GetBanner(number);
+        auto* banner = GetBanner(BannerIndex::FromUnderlying(number));
 
         auto* bannerElement = GetBannerElement();
         if (bannerElement == nullptr)
@@ -144,7 +149,7 @@ public:
     void OnMouseDown(rct_widgetindex widgetIndex) override
     {
         rct_widget* widget = &widgets[widgetIndex];
-        auto* banner = GetBanner(number);
+        auto* banner = GetBanner(GetBannerIndex());
         if (banner == nullptr)
         {
             Close();
@@ -177,7 +182,7 @@ public:
 
     void OnMouseUp(rct_widgetindex widgetIndex) override
     {
-        auto* banner = GetBanner(number);
+        auto* banner = GetBanner(GetBannerIndex());
         if (banner == nullptr)
         {
             Close();
@@ -207,7 +212,7 @@ public:
             {
                 textinput_cancel();
                 auto bannerSetStyle = BannerSetStyleAction(
-                    BannerSetStyleType::NoEntry, number, banner->flags ^ BANNER_FLAG_NO_ENTRY);
+                    BannerSetStyleType::NoEntry, GetBannerIndex(), banner->flags ^ BANNER_FLAG_NO_ENTRY);
                 GameActions::Execute(&bannerSetStyle);
                 break;
             }
@@ -223,7 +228,7 @@ public:
                 if (dropdownIndex == -1)
                     break;
 
-                auto bannerSetStyle = BannerSetStyleAction(BannerSetStyleType::PrimaryColour, number, dropdownIndex);
+                auto bannerSetStyle = BannerSetStyleAction(BannerSetStyleType::PrimaryColour, GetBannerIndex(), dropdownIndex);
                 GameActions::Execute(&bannerSetStyle);
                 break;
             }
@@ -231,7 +236,7 @@ public:
             {
                 if (dropdownIndex == -1)
                     break;
-                auto bannerSetStyle = BannerSetStyleAction(BannerSetStyleType::TextColour, number, dropdownIndex + 1);
+                auto bannerSetStyle = BannerSetStyleAction(BannerSetStyleType::TextColour, GetBannerIndex(), dropdownIndex + 1);
                 GameActions::Execute(&bannerSetStyle);
                 break;
             }
@@ -242,7 +247,7 @@ public:
     {
         if (widgetIndex == WIDX_BANNER_TEXT)
         {
-            auto bannerSetNameAction = BannerSetNameAction(number, std::string(text));
+            auto bannerSetNameAction = BannerSetNameAction(GetBannerIndex(), std::string(text));
             GameActions::Execute(&bannerSetNameAction);
         }
     }
@@ -265,7 +270,7 @@ public:
 
     void OnPrepareDraw() override
     {
-        auto* banner = GetBanner(number);
+        auto* banner = GetBanner(GetBannerIndex());
         if (banner == nullptr)
         {
             return;
diff --git a/src/openrct2-ui/windows/Sign.cpp b/src/openrct2-ui/windows/Sign.cpp
index d7e8a463c2..1554c83416 100644
--- a/src/openrct2-ui/windows/Sign.cpp
+++ b/src/openrct2-ui/windows/Sign.cpp
@@ -59,9 +59,14 @@ class SignWindow final : public Window
 private:
     bool _isSmall = false;
 
+    BannerIndex GetBannerIndex() const
+    {
+        return BannerIndex::FromUnderlying(number);
+    }
+
     void ShowTextInput()
     {
-        auto* banner = GetBanner(number);
+        auto* banner = GetBanner(GetBannerIndex());
         if (banner != nullptr)
         {
             auto bannerText = banner->GetText();
@@ -87,14 +92,14 @@ public:
     {
         number = windowNumber;
         _isSmall = isSmall;
-        auto* banner = GetBanner(number);
+        auto* banner = GetBanner(GetBannerIndex());
         if (banner == nullptr)
         {
             return false;
         }
 
         auto signViewPosition = banner->position.ToCoordsXY().ToTileCentre();
-        auto* tileElement = banner_get_tile_element(number);
+        auto* tileElement = banner_get_tile_element(GetBannerIndex());
         if (tileElement == nullptr)
             return false;
 
@@ -138,7 +143,7 @@ public:
 
     void OnMouseUp(rct_widgetindex widgetIndex) override
     {
-        auto* banner = GetBanner(number);
+        auto* banner = GetBanner(GetBannerIndex());
         if (banner == nullptr)
         {
             Close();
@@ -151,7 +156,7 @@ public:
                 break;
             case WIDX_SIGN_DEMOLISH:
             {
-                auto* tileElement = banner_get_tile_element(number);
+                auto* tileElement = banner_get_tile_element(GetBannerIndex());
                 if (tileElement == nullptr)
                 {
                     Close();
@@ -203,7 +208,7 @@ public:
                 if (dropdownIndex == -1)
                     return;
                 list_information_type = dropdownIndex;
-                auto signSetStyleAction = SignSetStyleAction(number, dropdownIndex, var_492, !_isSmall);
+                auto signSetStyleAction = SignSetStyleAction(GetBannerIndex(), dropdownIndex, var_492, !_isSmall);
                 GameActions::Execute(&signSetStyleAction);
                 break;
             }
@@ -212,7 +217,7 @@ public:
                 if (dropdownIndex == -1)
                     return;
                 var_492 = dropdownIndex;
-                auto signSetStyleAction = SignSetStyleAction(number, list_information_type, dropdownIndex, !_isSmall);
+                auto signSetStyleAction = SignSetStyleAction(GetBannerIndex(), list_information_type, dropdownIndex, !_isSmall);
                 GameActions::Execute(&signSetStyleAction);
                 break;
             }
@@ -227,7 +232,7 @@ public:
     {
         if (widgetIndex == WIDX_SIGN_TEXT && !text.empty())
         {
-            auto signSetNameAction = SignSetNameAction(number, std::string(text));
+            auto signSetNameAction = SignSetNameAction(GetBannerIndex(), std::string(text));
             GameActions::Execute(&signSetNameAction);
         }
     }
@@ -288,7 +293,7 @@ public:
     {
         RemoveViewport();
 
-        auto banner = GetBanner(number);
+        auto banner = GetBanner(GetBannerIndex());
         if (banner == nullptr)
         {
             return;
diff --git a/src/openrct2-ui/windows/TileInspector.cpp b/src/openrct2-ui/windows/TileInspector.cpp
index e1236a8729..9b5a039a01 100644
--- a/src/openrct2-ui/windows/TileInspector.cpp
+++ b/src/openrct2-ui/windows/TileInspector.cpp
@@ -2356,8 +2356,8 @@ static void WindowTileInspectorScrollpaint(rct_window* w, rct_drawpixelinfo* dpi
                 break;
             case TILE_ELEMENT_TYPE_BANNER:
                 snprintf(
-                    buffer, sizeof(buffer), "%s (%d)", language_get_string(STR_BANNER_WINDOW_TITLE),
-                    tileElement->AsBanner()->GetIndex());
+                    buffer, sizeof(buffer), "%s (%u)", language_get_string(STR_BANNER_WINDOW_TITLE),
+                    tileElement->AsBanner()->GetIndex().ToUnderlying());
                 typeName = buffer;
                 break;
             default:
diff --git a/src/openrct2-ui/windows/TopToolbar.cpp b/src/openrct2-ui/windows/TopToolbar.cpp
index 08d2369e4d..32c01e4d84 100644
--- a/src/openrct2-ui/windows/TopToolbar.cpp
+++ b/src/openrct2-ui/windows/TopToolbar.cpp
@@ -2005,7 +2005,7 @@ static void WindowTopToolbarSceneryToolDown(const ScreenCoordsXY& windowPos, rct
                 {
                     auto data = result->GetData<BannerPlaceActionResult>();
                     OpenRCT2::Audio::Play3D(OpenRCT2::Audio::SoundId::PlaceItem, result->Position);
-                    context_open_detail_window(WD_BANNER, data.bannerId);
+                    context_open_detail_window(WD_BANNER, data.bannerId.ToUnderlying());
                 }
             });
             GameActions::Execute(&bannerPlaceAction);
diff --git a/src/openrct2/Identifiers.h b/src/openrct2/Identifiers.h
index d4e2f1c557..aa008e87d9 100644
--- a/src/openrct2/Identifiers.h
+++ b/src/openrct2/Identifiers.h
@@ -15,3 +15,5 @@
 #include <limits>
 
 using ParkEntranceIndex = TIdentifier<uint8_t, std::numeric_limits<uint8_t>::max(), struct ParkEntranceIndexTag>;
+
+using BannerIndex = TIdentifier<uint16_t, std::numeric_limits<uint16_t>::max(), struct BannerIndexTag>;
diff --git a/src/openrct2/ParkFile.cpp b/src/openrct2/ParkFile.cpp
index 2bba172259..4b08dae306 100644
--- a/src/openrct2/ParkFile.cpp
+++ b/src/openrct2/ParkFile.cpp
@@ -983,9 +983,9 @@ namespace OpenRCT2
                     cs.Write(static_cast<uint32_t>(numBanners));
 
                     [[maybe_unused]] size_t numWritten = 0;
-                    for (BannerIndex i = 0; i < MAX_BANNERS; i++)
+                    for (BannerIndex::UnderlyingType i = 0; i < MAX_BANNERS; i++)
                     {
-                        auto banner = GetBanner(i);
+                        auto banner = GetBanner(BannerIndex::FromUnderlying(i));
                         if (banner != nullptr)
                         {
                             ReadWriteBanner(version, cs, *banner);
@@ -1001,9 +1001,9 @@ namespace OpenRCT2
                     {
                         std::vector<Banner> banners;
                         cs.ReadWriteVector(banners, [version, &cs](Banner& banner) { ReadWriteBanner(version, cs, banner); });
-                        for (size_t i = 0; i < banners.size(); i++)
+                        for (BannerIndex::UnderlyingType i = 0; i < banners.size(); i++)
                         {
-                            auto bannerIndex = static_cast<BannerIndex>(i);
+                            auto bannerIndex = BannerIndex::FromUnderlying(i);
                             auto banner = GetOrCreateBanner(bannerIndex);
                             if (banner != nullptr)
                             {
diff --git a/src/openrct2/actions/BannerPlaceAction.h b/src/openrct2/actions/BannerPlaceAction.h
index 3afc75ea50..54c945e42c 100644
--- a/src/openrct2/actions/BannerPlaceAction.h
+++ b/src/openrct2/actions/BannerPlaceAction.h
@@ -13,7 +13,7 @@
 
 struct BannerPlaceActionResult
 {
-    BannerIndex bannerId = BANNER_INDEX_NULL;
+    BannerIndex bannerId = BannerIndex::GetNull();
 };
 
 class BannerPlaceAction final : public GameActionBase<GameCommand::PlaceBanner>
diff --git a/src/openrct2/actions/BannerRemoveAction.cpp b/src/openrct2/actions/BannerRemoveAction.cpp
index eff4cc43cb..2495ad3ebd 100644
--- a/src/openrct2/actions/BannerRemoveAction.cpp
+++ b/src/openrct2/actions/BannerRemoveAction.cpp
@@ -62,7 +62,7 @@ GameActions::Result BannerRemoveAction::Query() const
     }
 
     auto bannerIndex = bannerElement->GetIndex();
-    if (bannerIndex == BANNER_INDEX_NULL)
+    if (bannerIndex == BannerIndex::GetNull())
     {
         log_error("Invalid banner index. index = ", bannerIndex);
         return GameActions::Result(GameActions::Status::InvalidParameters, STR_CANT_REMOVE_THIS, STR_NONE);
@@ -101,7 +101,7 @@ GameActions::Result BannerRemoveAction::Execute() const
     }
 
     auto bannerIndex = bannerElement->GetIndex();
-    if (bannerIndex == BANNER_INDEX_NULL)
+    if (bannerIndex == BannerIndex::GetNull())
     {
         log_error("Invalid banner index. index = ", bannerIndex);
         return GameActions::Result(GameActions::Status::InvalidParameters, STR_CANT_REMOVE_THIS, STR_NONE);
diff --git a/src/openrct2/actions/BannerSetNameAction.h b/src/openrct2/actions/BannerSetNameAction.h
index 42ea2b99bb..a129753a75 100644
--- a/src/openrct2/actions/BannerSetNameAction.h
+++ b/src/openrct2/actions/BannerSetNameAction.h
@@ -14,7 +14,7 @@
 class BannerSetNameAction final : public GameActionBase<GameCommand::SetBannerName>
 {
 private:
-    BannerIndex _bannerIndex{ BANNER_INDEX_NULL };
+    BannerIndex _bannerIndex{ BannerIndex::GetNull() };
     std::string _name;
 
 public:
diff --git a/src/openrct2/actions/BannerSetStyleAction.h b/src/openrct2/actions/BannerSetStyleAction.h
index 0a6beef6a6..06b86031b0 100644
--- a/src/openrct2/actions/BannerSetStyleAction.h
+++ b/src/openrct2/actions/BannerSetStyleAction.h
@@ -25,7 +25,7 @@ class BannerSetStyleAction final : public GameActionBase<GameCommand::SetBannerS
 {
 private:
     BannerSetStyleType _type{ BannerSetStyleType::Count };
-    BannerIndex _bannerIndex{ BANNER_INDEX_NULL };
+    BannerIndex _bannerIndex{ BannerIndex::GetNull() };
     uint8_t _parameter{};
 
 public:
diff --git a/src/openrct2/actions/GameAction.h b/src/openrct2/actions/GameAction.h
index 4a017bb1f5..7e5e89eb0a 100644
--- a/src/openrct2/actions/GameAction.h
+++ b/src/openrct2/actions/GameAction.h
@@ -12,6 +12,7 @@
 #include "../Game.h"
 #include "../common.h"
 #include "../core/DataSerialiser.h"
+#include "../core/Identifier.hpp"
 #include "../localisation/StringIds.h"
 #include "GameActionResult.h"
 
@@ -86,6 +87,13 @@ public:
         param = static_cast<T>(value);
     }
 
+    template<typename T, T TNull, typename TTag> void Visit(std::string_view name, TIdentifier<T, TNull, TTag>& param)
+    {
+        auto value = param.ToUnderlying();
+        Visit(name, value);
+        param = TIdentifier<T, TNull, TTag>::FromUnderlying(value);
+    }
+
     template<typename T, size_t _TypeID> void Visit(std::string_view name, NetworkObjectId_t<T, _TypeID>& param)
     {
         Visit(name, param.id);
diff --git a/src/openrct2/actions/LargeSceneryPlaceAction.h b/src/openrct2/actions/LargeSceneryPlaceAction.h
index 07f9d38330..4eb294bd79 100644
--- a/src/openrct2/actions/LargeSceneryPlaceAction.h
+++ b/src/openrct2/actions/LargeSceneryPlaceAction.h
@@ -17,7 +17,7 @@ struct LargeSceneryPlaceActionResult
 {
     uint8_t GroundFlags{ 0 };
     int32_t firstTileHeight{ 0 };
-    BannerIndex bannerId = BANNER_INDEX_NULL;
+    BannerIndex bannerId = BannerIndex::GetNull();
 };
 
 class LargeSceneryPlaceAction final : public GameActionBase<GameCommand::PlaceLargeScenery>
diff --git a/src/openrct2/actions/SignSetNameAction.h b/src/openrct2/actions/SignSetNameAction.h
index 4d69ceeffe..07019484eb 100644
--- a/src/openrct2/actions/SignSetNameAction.h
+++ b/src/openrct2/actions/SignSetNameAction.h
@@ -14,7 +14,7 @@
 class SignSetNameAction final : public GameActionBase<GameCommand::SetSignName>
 {
 private:
-    BannerIndex _bannerIndex{ BANNER_INDEX_NULL };
+    BannerIndex _bannerIndex{ BannerIndex::GetNull() };
     std::string _name;
 
 public:
diff --git a/src/openrct2/actions/SignSetStyleAction.h b/src/openrct2/actions/SignSetStyleAction.h
index 246ce8d23b..990554c669 100644
--- a/src/openrct2/actions/SignSetStyleAction.h
+++ b/src/openrct2/actions/SignSetStyleAction.h
@@ -14,7 +14,7 @@
 class SignSetStyleAction final : public GameActionBase<GameCommand::SetSignStyle>
 {
 private:
-    BannerIndex _bannerIndex{ BANNER_INDEX_NULL };
+    BannerIndex _bannerIndex{ BannerIndex::GetNull() };
     uint8_t _mainColour{};
     uint8_t _textColour{};
     bool _isLarge{};
diff --git a/src/openrct2/actions/WallPlaceAction.cpp b/src/openrct2/actions/WallPlaceAction.cpp
index 6fb3b83f3c..1d6053c34b 100644
--- a/src/openrct2/actions/WallPlaceAction.cpp
+++ b/src/openrct2/actions/WallPlaceAction.cpp
@@ -371,7 +371,7 @@ GameActions::Result WallPlaceAction::Execute() const
     wallElement->SetAcrossTrack(wallAcrossTrack);
 
     wallElement->SetEntryIndex(_wallType);
-    wallElement->SetBannerIndex(banner != nullptr ? banner->id : BANNER_INDEX_NULL);
+    wallElement->SetBannerIndex(banner != nullptr ? banner->id : BannerIndex::GetNull());
 
     if (wallEntry->flags & WALL_SCENERY_HAS_TERNARY_COLOUR)
     {
@@ -385,7 +385,7 @@ GameActions::Result WallPlaceAction::Execute() const
 
     res.Cost = wallEntry->price;
 
-    const auto bannerId = banner != nullptr ? banner->id : BANNER_INDEX_NULL;
+    const auto bannerId = banner != nullptr ? banner->id : BannerIndex::GetNull();
     res.SetData(WallPlaceActionResult{ wallElement->GetBaseZ(), bannerId });
 
     return res;
diff --git a/src/openrct2/actions/WallPlaceAction.h b/src/openrct2/actions/WallPlaceAction.h
index 094d813b5a..fdca3e5099 100644
--- a/src/openrct2/actions/WallPlaceAction.h
+++ b/src/openrct2/actions/WallPlaceAction.h
@@ -18,7 +18,7 @@
 struct WallPlaceActionResult
 {
     int32_t BaseHeight{};
-    BannerIndex BannerId = BANNER_INDEX_NULL;
+    BannerIndex BannerId = BannerIndex::GetNull();
 };
 
 class WallPlaceAction final : public GameActionBase<GameCommand::PlaceWall>
diff --git a/src/openrct2/core/DataSerialiserTraits.h b/src/openrct2/core/DataSerialiserTraits.h
index e4855f5068..ea0aa1536e 100644
--- a/src/openrct2/core/DataSerialiserTraits.h
+++ b/src/openrct2/core/DataSerialiserTraits.h
@@ -839,3 +839,24 @@ template<> struct DataSerializerTraits_t<TileCoordsXYZD>
         stream->Write(msg, strlen(msg));
     }
 };
+
+template<typename T, T TNull, typename TTag> struct DataSerializerTraits_t<TIdentifier<T, TNull, TTag>>
+{
+    static void encode(OpenRCT2::IStream* stream, const TIdentifier<T, TNull, TTag>& id)
+    {
+        stream->WriteValue(ByteSwapBE(id.ToUnderlying()));
+    }
+
+    static void decode(OpenRCT2::IStream* stream, TIdentifier<T, TNull, TTag>& id)
+    {
+        auto temp = ByteSwapBE(stream->ReadValue<T>());
+        id = TIdentifier<T, TNull, TTag>::FromUnderlying(temp);
+    }
+
+    static void log(OpenRCT2::IStream* stream, const TIdentifier<T, TNull, TTag>& id)
+    {
+        char msg[128] = {};
+        snprintf(msg, sizeof(msg), "Id(%u)", static_cast<uint32_t>(id.ToUnderlying()));
+        stream->Write(msg, strlen(msg));
+    }
+};
diff --git a/src/openrct2/core/Identifier.hpp b/src/openrct2/core/Identifier.hpp
index 22fe9b0981..e93f8f17ae 100644
--- a/src/openrct2/core/Identifier.hpp
+++ b/src/openrct2/core/Identifier.hpp
@@ -32,6 +32,8 @@ private:
     }
 
 public:
+    using UnderlyingType = T;
+
     constexpr TIdentifier() = default;
 
     static constexpr TIdentifier GetNull() noexcept
@@ -63,4 +65,14 @@ public:
     {
         return _handle != other;
     }
+
+    constexpr bool operator==(const TIdentifier& other) const noexcept
+    {
+        return _handle == other._handle;
+    }
+
+    constexpr bool operator!=(const TIdentifier& other) const noexcept
+    {
+        return _handle != other._handle;
+    }
 };
diff --git a/src/openrct2/core/OrcaStream.hpp b/src/openrct2/core/OrcaStream.hpp
index fbc330ae51..e5efb77ac9 100644
--- a/src/openrct2/core/OrcaStream.hpp
+++ b/src/openrct2/core/OrcaStream.hpp
@@ -12,6 +12,7 @@
 #include "../world/Location.hpp"
 #include "Crypt.h"
 #include "FileStream.h"
+#include "Identifier.hpp"
 #include "MemoryStream.h"
 
 #include <algorithm>
@@ -312,6 +313,21 @@ namespace OpenRCT2
                 }
             }
 
+            template<typename T, T TNullValue, typename TTag> void ReadWrite(TIdentifier<T, TNullValue, TTag>& value)
+            {
+                if (_mode == Mode::READING)
+                {
+                    T temp{};
+                    ReadWrite(temp);
+                    value = TIdentifier<T, TNullValue, TTag>::FromUnderlying(temp);
+                }
+                else
+                {
+                    auto temp = value.ToUnderlying();
+                    ReadWrite(temp);
+                }
+            }
+
             void ReadWrite(bool& value)
             {
                 uint8_t value8 = value ? 1 : 0;
diff --git a/src/openrct2/rct1/S4Importer.cpp b/src/openrct2/rct1/S4Importer.cpp
index aaae9dc72b..3a370e732d 100644
--- a/src/openrct2/rct1/S4Importer.cpp
+++ b/src/openrct2/rct1/S4Importer.cpp
@@ -1790,7 +1790,7 @@ namespace RCT1
                         wallElement->SetPrimaryColour(colourA);
                         wallElement->SetSecondaryColour(colourB);
                         wallElement->SetTertiaryColour(colourC);
-                        wallElement->SetBannerIndex(BANNER_INDEX_NULL);
+                        wallElement->SetBannerIndex(BannerIndex::GetNull());
                         wallElement->SetAcrossTrack(false);
                         wallElement->SetAnimationIsBackwards(false);
                         wallElement->SetSlope(edgeSlope);
@@ -1826,20 +1826,20 @@ namespace RCT1
                     if (index < std::size(_s4.banners))
                     {
                         auto srcBanner = &_s4.banners[index];
-                        auto dstBanner = GetOrCreateBanner(index);
+                        auto dstBanner = GetOrCreateBanner(BannerIndex::FromUnderlying(index));
                         if (dstBanner == nullptr)
                         {
-                            dst2->SetIndex(BANNER_INDEX_NULL);
+                            dst2->SetIndex(BannerIndex::GetNull());
                         }
                         else
                         {
                             ImportBanner(dstBanner, srcBanner);
-                            dst2->SetIndex(index);
+                            dst2->SetIndex(BannerIndex::FromUnderlying(index));
                         }
                     }
                     else
                     {
-                        dst2->SetIndex(BANNER_INDEX_NULL);
+                        dst2->SetIndex(BannerIndex::GetNull());
                     }
                     return 1;
                 }
diff --git a/src/openrct2/rct2/S6Importer.cpp b/src/openrct2/rct2/S6Importer.cpp
index df1dd8ac9e..3245943627 100644
--- a/src/openrct2/rct2/S6Importer.cpp
+++ b/src/openrct2/rct2/S6Importer.cpp
@@ -520,14 +520,14 @@ namespace RCT2
                 // This scenario breaks pathfinding. Create passages between the worlds. (List is grouped by neighbouring
                 // tiles.)
                 // clang-format off
-            FixLandOwnershipTilesWithOwnership(
-                {
-                    { 67, 94 }, { 68, 94 }, { 69, 94 },
-                    { 58, 24 }, { 58, 25 }, { 58, 26 }, { 58, 27 }, { 58, 28 }, { 58, 29 }, { 58, 30 }, { 58, 31 }, { 58, 32 },
-                    { 26, 44 }, { 26, 45 },
-                    { 32, 79 }, { 32, 80 }, { 32, 81 },
-                },
-                OWNERSHIP_OWNED);
+                FixLandOwnershipTilesWithOwnership(
+                    {
+                        { 67, 94 }, { 68, 94 }, { 69, 94 },
+                        { 58, 24 }, { 58, 25 }, { 58, 26 }, { 58, 27 }, { 58, 28 }, { 58, 29 }, { 58, 30 }, { 58, 31 }, { 58, 32 },
+                        { 26, 44 }, { 26, 45 },
+                        { 32, 79 }, { 32, 80 }, { 32, 81 },
+                    },
+                    OWNERSHIP_OWNED);
                 // clang-format on
             }
             else if (String::Equals(gScenarioFileName, "N America - Extreme Hawaiian Island.SC6"))
@@ -1364,7 +1364,7 @@ namespace RCT2
                     dst2->SetAnimationIsBackwards(src2->AnimationIsBackwards());
 
                     // Import banner information
-                    dst2->SetBannerIndex(BANNER_INDEX_NULL);
+                    dst2->SetBannerIndex(BannerIndex::GetNull());
                     auto entry = dst2->GetEntry();
                     if (entry != nullptr && entry->scrolling_mode != SCROLLING_MODE_NONE)
                     {
@@ -1372,15 +1372,15 @@ namespace RCT2
                         if (bannerIndex < std::size(_s6.banners))
                         {
                             auto srcBanner = &_s6.banners[bannerIndex];
-                            auto dstBanner = GetOrCreateBanner(bannerIndex);
+                            auto dstBanner = GetOrCreateBanner(BannerIndex::FromUnderlying(bannerIndex));
                             if (dstBanner == nullptr)
                             {
-                                dst2->SetBannerIndex(BANNER_INDEX_NULL);
+                                dst2->SetBannerIndex(BannerIndex::GetNull());
                             }
                             else
                             {
                                 ImportBanner(dstBanner, srcBanner);
-                                dst2->SetBannerIndex(src2->GetBannerIndex());
+                                dst2->SetBannerIndex(BannerIndex::FromUnderlying(src2->GetBannerIndex()));
                             }
                         }
                     }
@@ -1397,7 +1397,7 @@ namespace RCT2
                     dst2->SetSecondaryColour(src2->GetSecondaryColour());
 
                     // Import banner information
-                    dst2->SetBannerIndex(BANNER_INDEX_NULL);
+                    dst2->SetBannerIndex(BannerIndex::GetNull());
                     auto entry = dst2->GetEntry();
                     if (entry != nullptr && entry->scrolling_mode != SCROLLING_MODE_NONE)
                     {
@@ -1405,15 +1405,15 @@ namespace RCT2
                         if (bannerIndex < std::size(_s6.banners))
                         {
                             auto srcBanner = &_s6.banners[bannerIndex];
-                            auto dstBanner = GetOrCreateBanner(bannerIndex);
+                            auto dstBanner = GetOrCreateBanner(BannerIndex::FromUnderlying(bannerIndex));
                             if (dstBanner == nullptr)
                             {
-                                dst2->SetBannerIndex(BANNER_INDEX_NULL);
+                                dst2->SetBannerIndex(BannerIndex::GetNull());
                             }
                             else
                             {
                                 ImportBanner(dstBanner, srcBanner);
-                                dst2->SetBannerIndex(src2->GetBannerIndex());
+                                dst2->SetBannerIndex(BannerIndex::FromUnderlying(src2->GetBannerIndex()));
                             }
                         }
                     }
@@ -1431,20 +1431,20 @@ namespace RCT2
                     if (bannerIndex < std::size(_s6.banners))
                     {
                         auto srcBanner = &_s6.banners[bannerIndex];
-                        auto dstBanner = GetOrCreateBanner(bannerIndex);
+                        auto dstBanner = GetOrCreateBanner(BannerIndex::FromUnderlying(bannerIndex));
                         if (dstBanner == nullptr)
                         {
-                            dst2->SetIndex(BANNER_INDEX_NULL);
+                            dst2->SetIndex(BannerIndex::GetNull());
                         }
                         else
                         {
                             ImportBanner(dstBanner, srcBanner);
-                            dst2->SetIndex(bannerIndex);
+                            dst2->SetIndex(BannerIndex::FromUnderlying(bannerIndex));
                         }
                     }
                     else
                     {
-                        dst2->SetIndex(BANNER_INDEX_NULL);
+                        dst2->SetIndex(BannerIndex::GetNull());
                     }
                     break;
                 }
diff --git a/src/openrct2/scripting/bindings/world/ScTileElement.cpp b/src/openrct2/scripting/bindings/world/ScTileElement.cpp
index 1cdd6952f5..c00b4a2f09 100644
--- a/src/openrct2/scripting/bindings/world/ScTileElement.cpp
+++ b/src/openrct2/scripting/bindings/world/ScTileElement.cpp
@@ -1034,35 +1034,36 @@ namespace OpenRCT2::Scripting
     {
         auto ctx = GetContext()->GetScriptEngine().GetContext();
         BannerIndex idx = _element->GetBannerIndex();
-        if (idx == BANNER_INDEX_NULL)
+        if (idx == BannerIndex::GetNull())
             duk_push_null(ctx);
         else
-            duk_push_int(ctx, idx);
+            duk_push_int(ctx, idx.ToUnderlying());
         return DukValue::take_from_stack(ctx);
     }
     void ScTileElement::bannerIndex_set(uint16_t value)
     {
         ThrowIfGameStateNotMutable();
+
         switch (_element->GetType())
         {
             case TILE_ELEMENT_TYPE_LARGE_SCENERY:
             {
                 auto el = _element->AsLargeScenery();
-                el->SetBannerIndex(value);
+                el->SetBannerIndex(BannerIndex::FromUnderlying(value));
                 Invalidate();
                 break;
             }
             case TILE_ELEMENT_TYPE_WALL:
             {
                 auto el = _element->AsWall();
-                el->SetBannerIndex(value);
+                el->SetBannerIndex(BannerIndex::FromUnderlying(value));
                 Invalidate();
                 break;
             }
             case TILE_ELEMENT_TYPE_BANNER:
             {
                 auto el = _element->AsBanner();
-                el->SetIndex(value);
+                el->SetIndex(BannerIndex::FromUnderlying(value));
                 Invalidate();
                 break;
             }
diff --git a/src/openrct2/windows/Intent.h b/src/openrct2/windows/Intent.h
index 77c5ecbb03..962479ea52 100644
--- a/src/openrct2/windows/Intent.h
+++ b/src/openrct2/windows/Intent.h
@@ -10,6 +10,7 @@
 #pragma once
 
 #include "../common.h"
+#include "../core/Identifier.hpp"
 #include "../interface/Window.h"
 
 #include <map>
@@ -54,6 +55,12 @@ public:
     Intent* putExtra(uint32_t key, int32_t value);
     Intent* putExtra(uint32_t key, std::string value);
     Intent* putExtra(uint32_t key, close_callback value);
+
+    template<typename T, T TNull, typename TTag> Intent* putExtra(uint32_t key, const TIdentifier<T, TNull, TTag>& value)
+    {
+        const auto val = value.ToUnderlying();
+        return putExtra(key, static_cast<uint32_t>(val));
+    }
 };
 
 enum
diff --git a/src/openrct2/world/Banner.cpp b/src/openrct2/world/Banner.cpp
index 98b5c77457..6021e8226d 100644
--- a/src/openrct2/world/Banner.cpp
+++ b/src/openrct2/world/Banner.cpp
@@ -113,22 +113,22 @@ static ride_id_t banner_get_ride_index_at(const CoordsXYZ& bannerCoords)
 
 static BannerIndex BannerGetNewIndex()
 {
-    for (BannerIndex bannerIndex = 0; bannerIndex < MAX_BANNERS; bannerIndex++)
+    for (BannerIndex::UnderlyingType bannerIndex = 0; bannerIndex < MAX_BANNERS; bannerIndex++)
     {
         if (bannerIndex < _banners.size())
         {
             if (_banners[bannerIndex].IsNull())
             {
-                return bannerIndex;
+                return BannerIndex::FromUnderlying(bannerIndex);
             }
         }
         else
         {
             _banners.emplace_back();
-            return static_cast<BannerIndex>(_banners.size() - 1);
+            return BannerIndex::FromUnderlying(bannerIndex);
         }
     }
-    return BANNER_INDEX_NULL;
+    return BannerIndex::GetNull();
 }
 
 /**
@@ -238,12 +238,13 @@ ride_id_t banner_get_closest_ride_index(const CoordsXYZ& mapPos)
 
 void banner_reset_broken_index()
 {
-    for (BannerIndex bannerIndex = 0; bannerIndex < _banners.size(); bannerIndex++)
+    for (BannerIndex::UnderlyingType index = 0; index < _banners.size(); index++)
     {
-        auto tileElement = banner_get_tile_element(bannerIndex);
+        const auto bannerId = BannerIndex::FromUnderlying(index);
+        auto tileElement = banner_get_tile_element(bannerId);
         if (tileElement == nullptr)
         {
-            auto banner = GetBanner(bannerIndex);
+            auto banner = GetBanner(bannerId);
             if (banner != nullptr)
             {
                 banner->type = BANNER_NULL;
@@ -266,13 +267,14 @@ void fix_duplicated_banners()
             for (auto* bannerElement : OpenRCT2::TileElementsView<BannerElement>(bannerPos))
             {
                 auto bannerIndex = bannerElement->GetIndex();
-                if (bannerIndex == BANNER_INDEX_NULL)
+                if (bannerIndex == BannerIndex::GetNull())
                     continue;
 
-                if (activeBanners[bannerIndex])
+                const auto index = bannerIndex.ToUnderlying();
+                if (activeBanners[index])
                 {
                     log_info(
-                        "Duplicated banner with index %d found at x = %d, y = %d and z = %d.", bannerIndex, x, y,
+                        "Duplicated banner with index %d found at x = %d, y = %d and z = %d.", index, x, y,
                         bannerElement->base_height);
 
                     // Banner index is already in use by another banner, so duplicate it
@@ -282,7 +284,7 @@ void fix_duplicated_banners()
                         log_error("Failed to create new banner.");
                         continue;
                     }
-                    Guard::Assert(!activeBanners[newBanner->id]);
+                    Guard::Assert(!activeBanners[index]);
 
                     // Copy over the original banner, but update the location
                     const auto* oldBanner = GetBanner(bannerIndex);
@@ -299,7 +301,7 @@ void fix_duplicated_banners()
                 }
 
                 // Mark banner index as in-use
-                activeBanners[bannerIndex] = true;
+                activeBanners[index] = true;
             }
         }
     }
@@ -383,9 +385,10 @@ void UnlinkAllBannersForRide(ride_id_t rideId)
 
 Banner* GetBanner(BannerIndex id)
 {
-    if (id < _banners.size())
+    const auto index = id.ToUnderlying();
+    if (index < _banners.size())
     {
-        auto banner = &_banners[id];
+        auto banner = &_banners[index];
         if (banner != nullptr && !banner->IsNull())
         {
             return banner;
@@ -396,14 +399,15 @@ Banner* GetBanner(BannerIndex id)
 
 Banner* GetOrCreateBanner(BannerIndex id)
 {
-    if (id < MAX_BANNERS)
+    const auto index = id.ToUnderlying();
+    if (index < MAX_BANNERS)
     {
-        if (id >= _banners.size())
+        if (index >= _banners.size())
         {
-            _banners.resize(id + 1);
+            _banners.resize(index + 1);
         }
         // Create the banner
-        auto& banner = _banners[id];
+        auto& banner = _banners[index];
         banner.id = id;
         return &banner;
     }
diff --git a/src/openrct2/world/Banner.h b/src/openrct2/world/Banner.h
index e4ad35c2ec..4be4ddb115 100644
--- a/src/openrct2/world/Banner.h
+++ b/src/openrct2/world/Banner.h
@@ -9,6 +9,7 @@
 
 #pragma once
 
+#include "../Identifiers.h"
 #include "../common.h"
 #include "../ride/RideTypes.h"
 #include "Location.hpp"
@@ -19,17 +20,14 @@ class Formatter;
 struct TileElement;
 struct WallElement;
 
-using BannerIndex = uint16_t;
-
 constexpr ObjectEntryIndex BANNER_NULL = OBJECT_ENTRY_INDEX_NULL;
 constexpr size_t MAX_BANNERS = 8192;
-constexpr BannerIndex BANNER_INDEX_NULL = static_cast<BannerIndex>(-1);
 
 constexpr uint8_t SCROLLING_MODE_NONE = 255;
 
 struct Banner
 {
-    BannerIndex id = BANNER_INDEX_NULL;
+    BannerIndex id = BannerIndex::GetNull();
     ObjectEntryIndex type = BANNER_NULL;
     uint8_t flags{};
     std::string text;
diff --git a/src/openrct2/world/TileElement.cpp b/src/openrct2/world/TileElement.cpp
index 8599c899aa..4a5354bbc6 100644
--- a/src/openrct2/world/TileElement.cpp
+++ b/src/openrct2/world/TileElement.cpp
@@ -37,7 +37,7 @@ BannerIndex TileElement::GetBannerIndex() const
         {
             auto* sceneryEntry = AsLargeScenery()->GetEntry();
             if (sceneryEntry == nullptr || sceneryEntry->scrolling_mode == SCROLLING_MODE_NONE)
-                return BANNER_INDEX_NULL;
+                return BannerIndex::GetNull();
 
             return AsLargeScenery()->GetBannerIndex();
         }
@@ -45,14 +45,14 @@ BannerIndex TileElement::GetBannerIndex() const
         {
             auto* wallEntry = AsWall()->GetEntry();
             if (wallEntry == nullptr || wallEntry->scrolling_mode == SCROLLING_MODE_NONE)
-                return BANNER_INDEX_NULL;
+                return BannerIndex::GetNull();
 
             return AsWall()->GetBannerIndex();
         }
         case TILE_ELEMENT_TYPE_BANNER:
             return AsBanner()->GetIndex();
         default:
-            return BANNER_INDEX_NULL;
+            return BannerIndex::GetNull();
     }
 }
 
@@ -81,7 +81,7 @@ void TileElement::RemoveBannerEntry()
     auto banner = GetBanner(bannerIndex);
     if (banner != nullptr)
     {
-        window_close_by_number(WC_BANNER, bannerIndex);
+        window_close_by_number(WC_BANNER, bannerIndex.ToUnderlying());
         DeleteBanner(banner->id);
     }
 }
diff --git a/src/openrct2/world/TileInspector.cpp b/src/openrct2/world/TileInspector.cpp
index 924ed2b9df..7a50ac4dc0 100644
--- a/src/openrct2/world/TileInspector.cpp
+++ b/src/openrct2/world/TileInspector.cpp
@@ -328,7 +328,7 @@ namespace OpenRCT2::TileInspector
         {
             // Check if the element to be pasted refers to a banner index
             auto bannerIndex = element.GetBannerIndex();
-            if (bannerIndex != BANNER_INDEX_NULL)
+            if (bannerIndex != BannerIndex::GetNull())
             {
                 // The element to be pasted refers to a banner index - make a copy of it
                 auto newBanner = CreateBanner();