diff --git a/src/battle_pyramid_bag.c b/src/battle_pyramid_bag.c
index 8fee57855..5537b302e 100644
--- a/src/battle_pyramid_bag.c
+++ b/src/battle_pyramid_bag.c
@@ -1428,7 +1428,7 @@ static u8 sub_81C6D08(u8 windowArrayId)
 static u8 sub_81C6D24(u8 windowArrayId)
 {
     u8 *windowId = &gPyramidBagResources->windowIds[windowArrayId];
-    if (*windowId == 0xFF)
+    if (*windowId == WINDOW_NONE)
     {
         *windowId = AddWindow(&gUnknown_0861F350[windowArrayId]);
         DrawStdFrameWithCustomTileAndPalette(*windowId, FALSE, 1, 0xE);
@@ -1440,13 +1440,13 @@ static u8 sub_81C6D24(u8 windowArrayId)
 static void sub_81C6D6C(u8 windowArrayId)
 {
     u8 *windowId = &gPyramidBagResources->windowIds[windowArrayId];
-    if (*windowId != 0xFF)
+    if (*windowId != WINDOW_NONE)
     {
         ClearStdWindowAndFrameToTransparent(*windowId, FALSE);
         ClearWindowTilemap(*windowId);
         RemoveWindow(*windowId);
         ScheduleBgCopyTilemapToVram(1);
-        *windowId = 0xFF;
+        *windowId = WINDOW_NONE;
     }
 }
 
diff --git a/src/item_menu.c b/src/item_menu.c
index 375e15cab..89374c5d2 100755
--- a/src/item_menu.c
+++ b/src/item_menu.c
@@ -2390,7 +2390,7 @@ u8 sub_81AE124(u8 which)
 u8 BagMenu_AddWindow(u8 which)
 {
     u8 *ptr = &gBagMenu->windowPointers[which];
-    if (*ptr == 0xFF)
+    if (*ptr == WINDOW_NONE)
     {
         *ptr = AddWindow(&sContextMenuWindowTemplates[which]);
         DrawStdFrameWithCustomTileAndPalette(*ptr, 0, 1, 14);
@@ -2402,20 +2402,20 @@ u8 BagMenu_AddWindow(u8 which)
 void BagMenu_RemoveWindow(u8 which)
 {
     u8 *ptr = &gBagMenu->windowPointers[which];
-    if (*ptr != 0xFF)
+    if (*ptr != WINDOW_NONE)
     {
         ClearStdWindowAndFrameToTransparent(*ptr, FALSE);
         ClearWindowTilemap(*ptr);
         RemoveWindow(*ptr);
         ScheduleBgCopyTilemapToVram(1);
-        *ptr = 0xFF;
+        *ptr = WINDOW_NONE;
     }
 }
 
 u8 AddItemMessageWindow(u8 which)
 {
     u8 *ptr = &gBagMenu->windowPointers[which];
-    if (*ptr == 0xFF)
+    if (*ptr == WINDOW_NONE)
         *ptr = AddWindow(&sContextMenuWindowTemplates[which]);
     return *ptr;
 }
@@ -2423,14 +2423,14 @@ u8 AddItemMessageWindow(u8 which)
 void BagMenu_RemoveBagItemMessageWindow(u8 which)
 {
     u8 *ptr = &gBagMenu->windowPointers[which];
-    if (*ptr != 0xFF)
+    if (*ptr != WINDOW_NONE)
     {
         ClearDialogWindowAndFrameToTransparent(*ptr, FALSE);
         // This ClearWindowTilemap call is redundant, since ClearDialogWindowAndFrameToTransparent already calls it.
         ClearWindowTilemap(*ptr);
         RemoveWindow(*ptr);
         ScheduleBgCopyTilemapToVram(1);
-        *ptr = 0xFF;
+        *ptr = WINDOW_NONE;
     }
 }
 
diff --git a/src/match_call.c b/src/match_call.c
index 68b630d6b..fb8ebc98c 100644
--- a/src/match_call.c
+++ b/src/match_call.c
@@ -1168,7 +1168,7 @@ static bool32 LoadMatchCallWindowGfx(u8 taskId)
 {
     s16 *taskData = gTasks[taskId].data;
     taskData[2] = AddWindow(&sMatchCallTextWindow);
-    if (taskData[2] == 0xFF)
+    if (taskData[2] == WINDOW_NONE)
     {
         DestroyTask(taskId);
         return FALSE;
diff --git a/src/menu.c b/src/menu.c
index 4813f7b02..86e5caac2 100644
--- a/src/menu.c
+++ b/src/menu.c
@@ -144,8 +144,8 @@ void task_free_buf_after_copying_tile_data_to_vram(u8 taskId);
 void InitStandardTextBoxWindows(void)
 {
     InitWindows(sStandardTextBox_WindowTemplates);
-    sStartMenuWindowId = 0xFF;
-    sMapNamePopupWindowId = 0xFF;
+    sStartMenuWindowId = WINDOW_NONE;
+    sMapNamePopupWindowId = WINDOW_NONE;
 }
 
 void FreeAllOverworldWindowBuffers(void)
@@ -490,7 +490,7 @@ u8 GetPlayerTextSpeedDelay(void)
 
 u8 sub_81979C4(u8 a1)
 {
-    if (sStartMenuWindowId == 0xFF)
+    if (sStartMenuWindowId == WINDOW_NONE)
         sStartMenuWindowId = sub_8198AA4(0, 0x16, 1, 7, (a1 * 2) + 2, 0xF, 0x139);
     return sStartMenuWindowId;
 }
@@ -502,10 +502,10 @@ u8 GetStartMenuWindowId(void)
 
 void RemoveStartMenuWindow(void)
 {
-    if (sStartMenuWindowId != 0xFF)
+    if (sStartMenuWindowId != WINDOW_NONE)
     {
         RemoveWindow(sStartMenuWindowId);
-        sStartMenuWindowId = 0xFF;
+        sStartMenuWindowId = WINDOW_NONE;
     }
 }
 
@@ -521,7 +521,7 @@ u16 sub_8197A38(void)
 
 u8 AddMapNamePopUpWindow(void)
 {
-    if (sMapNamePopupWindowId == 0xFF)
+    if (sMapNamePopupWindowId == WINDOW_NONE)
         sMapNamePopupWindowId = sub_8198AA4(0, 1, 1, 10, 3, 14, 0x107);
     return sMapNamePopupWindowId;
 }
@@ -533,10 +533,10 @@ u8 GetMapNamePopUpWindowId(void)
 
 void RemoveMapNamePopUpWindow(void)
 {
-    if (sMapNamePopupWindowId != 0xFF)
+    if (sMapNamePopupWindowId != WINDOW_NONE)
     {
         RemoveWindow(sMapNamePopupWindowId);
-        sMapNamePopupWindowId = 0xFF;
+        sMapNamePopupWindowId = WINDOW_NONE;
     }
 }
 
@@ -815,7 +815,7 @@ void sub_8198180(const u8 *string, u8 a2, bool8 copyToVram)
 {
     u16 width = 0;
 
-    if (sWindowId != 0xFF)
+    if (sWindowId != WINDOW_NONE)
     {
         PutWindowTilemap(sWindowId);
         FillWindowPixelBuffer(sWindowId, PIXEL_FILL(15));
@@ -837,7 +837,7 @@ void sub_8198204(const u8 *string, const u8 *string2, u8 a3, u8 a4, bool8 copyTo
     u8 color[3];
     u16 width = 0;
 
-    if (sWindowId != 0xFF)
+    if (sWindowId != WINDOW_NONE)
     {
         if (a3 != 0)
         {
@@ -872,13 +872,13 @@ void sub_8198204(const u8 *string, const u8 *string2, u8 a3, u8 a4, bool8 copyTo
 
 void sub_81982D8(void)
 {
-    if (sWindowId != 0xFF)
+    if (sWindowId != WINDOW_NONE)
         CopyWindowToVram(sWindowId, 3);
 }
 
 void sub_81982F0(void)
 {
-    if (sWindowId != 0xFF)
+    if (sWindowId != WINDOW_NONE)
     {
         FillWindowPixelBuffer(sWindowId, PIXEL_FILL(15));
         CopyWindowToVram(sWindowId, 3);
@@ -887,13 +887,13 @@ void sub_81982F0(void)
 
 void sub_8198314(void)
 {
-    if (sWindowId != 0xFF)
+    if (sWindowId != WINDOW_NONE)
     {
         FillWindowPixelBuffer(sWindowId, PIXEL_FILL(0));
         ClearWindowTilemap(sWindowId);
         CopyWindowToVram(sWindowId, 3);
         RemoveWindow(sWindowId);
-        sWindowId = 0xFF;
+        sWindowId = WINDOW_NONE;
     }
 }
 
diff --git a/src/menu_specialized.c b/src/menu_specialized.c
index 74e3455c3..cdf0137cd 100644
--- a/src/menu_specialized.c
+++ b/src/menu_specialized.c
@@ -216,14 +216,14 @@ bool8 sub_81D1C44(u8 count)
         return FALSE;
 
     for (i = 0; i < ARRAY_COUNT(sUnknown_0203CF48); i++)
-        sUnknown_0203CF48[i] = 0xFF;
+        sUnknown_0203CF48[i] = WINDOW_NONE;
 
     return TRUE;
 }
 
 u8 sub_81D1C84(u8 a0)
 {
-    if (sUnknown_0203CF48[a0] == 0xFF)
+    if (sUnknown_0203CF48[a0] == WINDOW_NONE)
     {
         if (a0 == 2)
         {
@@ -245,7 +245,7 @@ void sub_81D1D04(u8 a0)
     ClearStdWindowAndFrameToTransparent(sUnknown_0203CF48[a0], 0);
     ClearWindowTilemap(sUnknown_0203CF48[a0]);
     RemoveWindow(sUnknown_0203CF48[a0]);
-    sUnknown_0203CF48[a0] = 0xFF;
+    sUnknown_0203CF48[a0] = WINDOW_NONE;
 }
 
 static u8 sub_81D1D34(u8 a0)
diff --git a/src/party_menu.c b/src/party_menu.c
index 95c41ac05..dbb5cf0e6 100755
--- a/src/party_menu.c
+++ b/src/party_menu.c
@@ -443,7 +443,7 @@ static void InitPartyMenu(u8 menuType, u8 layout, u8 partyAction, bool8 keepCurs
         for (i = 0; i < ARRAY_COUNT(sPartyMenuInternal->data); i++)
             sPartyMenuInternal->data[i] = 0;
         for (i = 0; i < ARRAY_COUNT(sPartyMenuInternal->windowId); i++)
-            sPartyMenuInternal->windowId[i] = 0xFF;
+            sPartyMenuInternal->windowId[i] = WINDOW_NONE;
 
         if (!keepCursorPos)
             gPartyMenu.slotId = 0;
@@ -2371,11 +2371,11 @@ static void DisplayPartyPokemonDescriptionText(u8 stringID, struct PartyMenuBox
 
 static void PartyMenuRemoveWindow(u8 *ptr)
 {
-    if (*ptr != 0xFF)
+    if (*ptr != WINDOW_NONE)
     {
         ClearStdWindowAndFrameToTransparent(*ptr, 0);
         RemoveWindow(*ptr);
-        *ptr = 0xFF;
+        *ptr = WINDOW_NONE;
         ScheduleBgCopyTilemapToVram(2);
     }
 }
@@ -2384,7 +2384,7 @@ void DisplayPartyMenuStdMessage(u32 stringId)
 {
     u8 *windowPtr = &sPartyMenuInternal->windowId[1];
 
-    if (*windowPtr != 0xFF)
+    if (*windowPtr != WINDOW_NONE)
         PartyMenuRemoveWindow(windowPtr);
 
     if (stringId != PARTY_MSG_NONE)
diff --git a/src/player_pc.c b/src/player_pc.c
index 1f293a195..447fa82c1 100644
--- a/src/player_pc.c
+++ b/src/player_pc.c
@@ -889,7 +889,7 @@ static void sub_816BC58(void)
 static u8 sub_816BC7C(u8 a)
 {
     u8 *windowIdLoc = &(gUnknown_0203BCC4->windowIds[a]);
-    if (*windowIdLoc == 0xFF)
+    if (*windowIdLoc == WINDOW_NONE)
     {
         *windowIdLoc = AddWindow(&gUnknown_085DFF5C[a]);
         DrawStdFrameWithCustomTileAndPalette(*windowIdLoc, FALSE, 0x214, 0xE);
@@ -901,13 +901,13 @@ static u8 sub_816BC7C(u8 a)
 static void sub_816BCC4(u8 a)
 {
     u8 *windowIdLoc = &(gUnknown_0203BCC4->windowIds[a]);
-    if (*windowIdLoc != 0xFF)
+    if (*windowIdLoc != WINDOW_NONE)
     {
         ClearStdWindowAndFrameToTransparent(*windowIdLoc, FALSE);
         ClearWindowTilemap(*windowIdLoc);
         ScheduleBgCopyTilemapToVram(0);
         RemoveWindow(*windowIdLoc);
-        *windowIdLoc = 0xFF;
+        *windowIdLoc = WINDOW_NONE;
     }
 }
 
diff --git a/src/pokemon_summary_screen.c b/src/pokemon_summary_screen.c
index b3cc1e516..53ec7c1d1 100644
--- a/src/pokemon_summary_screen.c
+++ b/src/pokemon_summary_screen.c
@@ -2680,7 +2680,7 @@ static void ResetWindows(void)
     for (i = 0; i < PSS_LABEL_WINDOW_END; i++)
         FillWindowPixelBuffer(i, PIXEL_FILL(0));
     for (i = 0; i < ARRAY_COUNT(sMonSummaryScreen->windowIds); i++)
-        sMonSummaryScreen->windowIds[i] = 0xFF;
+        sMonSummaryScreen->windowIds[i] = WINDOW_NONE;
 }
 
 static void PrintTextOnWindow(u8 windowId, const u8 *string, u8 x, u8 y, u8 lineSpacing, u8 colorId)
@@ -2938,7 +2938,7 @@ static void ClearPageWindowTilemaps(u8 page)
 static u8 AddWindowFromTemplateList(const struct WindowTemplate *template, u8 templateId)
 {
     u8 *windowIdPtr = &sMonSummaryScreen->windowIds[templateId];
-    if (*windowIdPtr == 0xFF)
+    if (*windowIdPtr == WINDOW_NONE)
     {
         *windowIdPtr = AddWindow(&template[templateId]);
         FillWindowPixelBuffer(*windowIdPtr, PIXEL_FILL(0));
@@ -2949,11 +2949,11 @@ static u8 AddWindowFromTemplateList(const struct WindowTemplate *template, u8 te
 static void RemoveWindowByIndex(u8 windowIndex)
 {
     u8 *windowIdPtr = &sMonSummaryScreen->windowIds[windowIndex];
-    if (*windowIdPtr != 0xFF)
+    if (*windowIdPtr != WINDOW_NONE)
     {
         ClearWindowTilemap(*windowIdPtr);
         RemoveWindow(*windowIdPtr);
-        *windowIdPtr = 0xFF;
+        *windowIdPtr = WINDOW_NONE;
     }
 }
 
@@ -2962,7 +2962,7 @@ static void PrintPageSpecificText(u8 pageIndex)
     u16 i;
     for (i = 0; i < ARRAY_COUNT(sMonSummaryScreen->windowIds); i++)
     {
-        if (sMonSummaryScreen->windowIds[i] != 0xFF)
+        if (sMonSummaryScreen->windowIds[i] != WINDOW_NONE)
             FillWindowPixelBuffer(sMonSummaryScreen->windowIds[i], PIXEL_FILL(0));
     }
     sTextPrinterFunctions[pageIndex]();
diff --git a/src/pokenav_match_call_ui.c b/src/pokenav_match_call_ui.c
index 2d89f9c39..11bb30162 100644
--- a/src/pokenav_match_call_ui.c
+++ b/src/pokenav_match_call_ui.c
@@ -987,7 +987,7 @@ bool32 CopyPokenavListMenuTemplate(struct PokenavSub17Substruct *dest, const str
     window.baseBlock = a3 + 2;
 
     dest->listWindow.windowId = AddWindow(&window);
-    if (dest->listWindow.windowId == 0xFF)
+    if (dest->listWindow.windowId == WINDOW_NONE)
         return FALSE;
 
     dest->listWindow.unkA = 0;
diff --git a/src/starter_choose.c b/src/starter_choose.c
index f7ffcfc2c..587169841 100644
--- a/src/starter_choose.c
+++ b/src/starter_choose.c
@@ -613,7 +613,7 @@ static void ClearStarterLabel(void)
     FillWindowPixelBuffer(sStarterLabelWindowId, PIXEL_FILL(0));
     ClearWindowTilemap(sStarterLabelWindowId);
     RemoveWindow(sStarterLabelWindowId);
-    sStarterLabelWindowId = 0xFF;
+    sStarterLabelWindowId = WINDOW_NONE;
     SetGpuReg(REG_OFFSET_WIN0H, 0);
     SetGpuReg(REG_OFFSET_WIN0V, 0);
     ScheduleBgCopyTilemapToVram(0);
diff --git a/src/union_room_chat.c b/src/union_room_chat.c
index 75464529f..131c57bbb 100755
--- a/src/union_room_chat.c
+++ b/src/union_room_chat.c
@@ -2724,7 +2724,7 @@ static void AddYesNoMenuAt(u8 left, u8 top, u8 initialCursorPos)
     template.paletteNum = 14;
     template.baseBlock = 0x52;
     sDisplay->yesNoMenuWindowId = AddWindow(&template);
-    if (sDisplay->yesNoMenuWindowId != 0xFF)
+    if (sDisplay->yesNoMenuWindowId != WINDOW_NONE)
     {
         FillWindowPixelBuffer(sDisplay->yesNoMenuWindowId, PIXEL_FILL(1));
         PutWindowTilemap(sDisplay->yesNoMenuWindowId);
@@ -2778,7 +2778,7 @@ static void AddStdMessageWindow(int msgId, u16 bg0vofs)
 
     sDisplay->messageWindowId = AddWindow(&template);
     windowId = sDisplay->messageWindowId;
-    if (sDisplay->messageWindowId == 0xFF)
+    if (sDisplay->messageWindowId == WINDOW_NONE)
         return;
 
     if (sDisplayStdMessages[msgId].hasPlaceholders)