diff --git a/charmap.txt b/charmap.txt
index c26c07e78b..7271c621ca 100644
--- a/charmap.txt
+++ b/charmap.txt
@@ -61,6 +61,13 @@ UP_ARROW    = 79
 DOWN_ARROW  = 7A
 LEFT_ARROW  = 7B
 RIGHT_ARROW = 7C
+@ Case-fixing/unfixing chars
+@ These are 1-2 pixel spaces in vanilla.
+@ 7D collides with 'ヲ' in JP,
+@ but that kana is practically unused in JP text.
+FIXED_CASE  = 7D
+UNFIX_CASE  = 7E
+
 SUPER_E     = 84
 '<'         = 85
 '>'         = 86
@@ -347,6 +354,10 @@ ARCHIE         = FD 0A
 MAXIE          = FD 0B
 KYOGRE         = FD 0C
 GROUDON        = FD 0D
+@ Like STR_VAR_X, but prepends CHAR_FIXED_CASE
+STR_VAR_1_FIXED  = FD 82
+STR_VAR_2_FIXED  = FD 83
+STR_VAR_3_FIXED  = FD 84
 
 @ battle string placeholders
 
diff --git a/data/text/pc_transfer.inc b/data/text/pc_transfer.inc
index 3fa255340b..01fe80a426 100644
--- a/data/text/pc_transfer.inc
+++ b/data/text/pc_transfer.inc
@@ -1,11 +1,11 @@
 gText_PkmnTransferredSomeonesPC::
-	.string "{STR_VAR_2} was transferred to\n"
+	.string "{STR_VAR_2_FIXED} was transferred to\n"
 	.string "SOMEONE'S PC.\p"
 	.string "It was placed in \n"
 	.string "BOX “{STR_VAR_1}.”$"
 
 gText_PkmnTransferredLanettesPC::
-	.string "{STR_VAR_2} was transferred to\n"
+	.string "{STR_VAR_2_FIXED} was transferred to\n"
 	.string "LANETTE'S PC.\p"
 	.string "It was placed in \n"
 	.string "BOX “{STR_VAR_1}.”$"
@@ -13,13 +13,13 @@ gText_PkmnTransferredLanettesPC::
 gText_PkmnTransferredSomeonesPCBoxFull::
 	.string "BOX “{STR_VAR_3}” on\n"
 	.string "SOMEONE'S PC was full.\p"
-	.string "{STR_VAR_2} was transferred to\n"
+	.string "{STR_VAR_2_FIXED} was transferred to\n"
 	.string "BOX “{STR_VAR_1}.”$"
 
 gText_PkmnTransferredLanettesPCBoxFull::
 	.string "BOX “{STR_VAR_3}” on\n"
 	.string "LANETTE'S PC was full.\p"
-	.string "{STR_VAR_2} was transferred to\n"
+	.string "{STR_VAR_2_FIXED} was transferred to\n"
 	.string "BOX “{STR_VAR_1}.”$"
 
 gText_NoMoreRoomForPokemon::
diff --git a/data/text/save.inc b/data/text/save.inc
index 4d17327c9b..4c16fd2fe6 100644
--- a/data/text/save.inc
+++ b/data/text/save.inc
@@ -7,14 +7,14 @@ gText_AlreadySavedFile::
 	.string "Is it okay to overwrite it?$"
 
 gText_SavingDontTurnOff::
-	.string "SAVING…\n"
+	.fixstr "SAVING…\n"
 	.string "DON'T TURN OFF THE POWER.$"
 
 gText_PlayerSavedGame::
 	.string "{PLAYER} saved the game.$"
 
 gText_DifferentSaveFile::
-	.string "WARNING!\p"
+	.string "{FIXED_CASE}WARNING!{UNFIX_CASE}\p"
 	.string "There is a different game file that\n"
 	.string "is already saved.\p"
 	.string "If you save now, the other file's\n"
@@ -29,5 +29,5 @@ gText_SaveError::
 	.string "backup memory.$"
 
 gText_SavingDontTurnOffPower::
-	.string "SAVING…\n"
+	.fixstr "SAVING…\n"
 	.string "DON'T TURN OFF THE POWER.$"
diff --git a/gflib/characters.h b/gflib/characters.h
index 8ed440e63a..3b00fa1eea 100644
--- a/gflib/characters.h
+++ b/gflib/characters.h
@@ -77,6 +77,9 @@
 #define CHAR_DOWN_ARROW        0x7A
 #define CHAR_LEFT_ARROW        0x7B
 #define CHAR_RIGHT_ARROW       0x7C
+// Case-fixing characters
+#define CHAR_FIXED_CASE        0x7D
+#define CHAR_UNFIX_CASE        0x7E
 //
 #define CHAR_SUPER_E           0x84
 #define CHAR_LESS_THAN         0x85
@@ -262,6 +265,10 @@
 #define PLACEHOLDER_ID_MAXIE         0xB
 #define PLACEHOLDER_ID_KYOGRE        0xC
 #define PLACEHOLDER_ID_GROUDON       0xD
+// Fixed-case placeholders
+// These behave the same as their (id & 0x7F),
+// but prepend CHAR_FIXED_CASE
+#define PLACEHOLDER_FIXED_MASK       0x80
 
 // battle placeholders are located in battle_message.h
 
diff --git a/gflib/string_util.c b/gflib/string_util.c
index f4a20d118a..9aef8d543a 100644
--- a/gflib/string_util.c
+++ b/gflib/string_util.c
@@ -26,11 +26,29 @@ static const s32 sPowersOfTen[] =
     1000000000,
 };
 
+// Tries to determine whether `str` is safe to prepend a ctrl char to
+// gStringVarX are always safe, as well as stack allocated IWRAM
+// (if `length mod 4` is 1 or 2)
+bool32 IsStringAddrSafe(u8 *str, u32 length)
+{
+    if (((u32)str) >> 24 == 3)
+        return (str >= gStackBase && (length & 3) && (length & 3) <= 2);
+    return (str >= gStringVar1 && str < sUnknownStringVar);
+}
+
 u8 *StringCopy_Nickname(u8 *dest, const u8 *src)
 {
-    u8 i;
+    u32 i;
     u32 limit = POKEMON_NAME_LENGTH;
 
+    if (DECAP_ENABLED && !DECAP_NICKNAMES)
+    {
+        if (IsStringAddrSafe(dest, limit) && *src != CHAR_FIXED_CASE)
+            *dest++ = CHAR_FIXED_CASE;
+        else if (*src == CHAR_FIXED_CASE)
+            *dest++ = *src++;
+    }
+
     for (i = 0; i < limit; i++)
     {
         dest[i] = src[i];
@@ -48,6 +66,9 @@ u8 *StringGet_Nickname(u8 *str)
     u8 i;
     u32 limit = POKEMON_NAME_LENGTH;
 
+    if (DECAP_ENABLED && !DECAP_NICKNAMES && *str == CHAR_FIXED_CASE)
+        str++;
+
     for (i = 0; i < limit; i++)
         if (str[i] == EOS)
             return &str[i];
@@ -61,6 +82,9 @@ u8 *StringCopy_PlayerName(u8 *dest, const u8 *src)
     s32 i;
     s32 limit = PLAYER_NAME_LENGTH;
 
+    if (DECAP_ENABLED && !DECAP_NICKNAMES && IsStringAddrSafe(dest, limit) && *src != CHAR_FIXED_CASE)
+        *dest++ = CHAR_FIXED_CASE;
+
     for (i = 0; i < limit; i++)
     {
         dest[i] = src[i];
@@ -75,6 +99,10 @@ u8 *StringCopy_PlayerName(u8 *dest, const u8 *src)
 
 u8 *StringCopy(u8 *dest, const u8 *src)
 {
+    // If `src` is mirrored, prepend fixed-case char
+    if (DECAP_ENABLED && DECAP_MIRRORING && IsMirrorPtr(src) && *src != CHAR_FIXED_CASE)
+        *dest++ = CHAR_FIXED_CASE;
+
     while (*src != EOS)
     {
         *dest = *src;
@@ -124,6 +152,14 @@ u16 StringLength(const u8 *str)
 
 s32 StringCompare(const u8 *str1, const u8 *str2)
 {
+    // Ignore leading fixed-case char
+    if (DECAP_ENABLED)
+    {
+        if (*str1 == CHAR_FIXED_CASE)
+            str1++;
+        if (*str2 == CHAR_FIXED_CASE)
+            str2++;
+    }
     while (*str1 == *str2)
     {
         if (*str1 == EOS)
@@ -137,6 +173,14 @@ s32 StringCompare(const u8 *str1, const u8 *str2)
 
 s32 StringCompareN(const u8 *str1, const u8 *str2, u32 n)
 {
+    // Ignore leading fixed-case char
+    if (DECAP_ENABLED)
+    {
+        if (*str1 == CHAR_FIXED_CASE)
+            str1++;
+        if (*str2 == CHAR_FIXED_CASE)
+            str2++;
+    }
     while (*str1 == *str2)
     {
         if (*str1 == EOS)
@@ -335,6 +379,7 @@ u8 *ConvertIntToHexStringN(u8 *dest, s32 value, enum StringConvertMode mode, u8
 
 u8 *StringExpandPlaceholders(u8 *dest, const u8 *src)
 {
+    bool32 fixedCase = FALSE;
     for (;;)
     {
         u8 c = *src++;
@@ -345,7 +390,20 @@ u8 *StringExpandPlaceholders(u8 *dest, const u8 *src)
         {
         case PLACEHOLDER_BEGIN:
             placeholderId = *src++;
-            expandedString = GetExpandedPlaceholder(placeholderId);
+            if (DECAP_ENABLED)
+            {
+                // Handle fixed-case versions of placeholders
+                if (!fixedCase && (placeholderId & PLACEHOLDER_FIXED_MASK || placeholderId == PLACEHOLDER_ID_PLAYER))
+                {
+                    *dest++ = CHAR_FIXED_CASE;
+                    expandedString = GetExpandedPlaceholder(placeholderId & ~PLACEHOLDER_FIXED_MASK);
+                    dest = StringExpandPlaceholders(dest, expandedString);
+                    *dest++ = CHAR_UNFIX_CASE;
+                    *dest = EOS;
+                    break;
+                }
+            }
+            expandedString = GetExpandedPlaceholder(placeholderId & ~PLACEHOLDER_FIXED_MASK);
             dest = StringExpandPlaceholders(dest, expandedString);
             break;
         case EXT_CTRL_CODE_BEGIN:
@@ -372,8 +430,19 @@ u8 *StringExpandPlaceholders(u8 *dest, const u8 *src)
             }
             break;
         case EOS:
+            if (DECAP_ENABLED && fixedCase)
+                *dest++ = CHAR_UNFIX_CASE;
             *dest = EOS;
             return dest;
+        #if DECAP_ENABLED
+        case CHAR_UNFIX_CASE:
+            fixedCase = FALSE;
+            *dest++ = c;
+            break;
+        case CHAR_FIXED_CASE:
+            fixedCase = TRUE;
+        // fallthrough
+        #endif
         case CHAR_PROMPT_SCROLL:
         case CHAR_PROMPT_CLEAR:
         case CHAR_NEWLINE:
@@ -700,6 +769,9 @@ static const u8 *SkipExtCtrlCode(const u8 *s)
         s += GetExtCtrlCodeLength(*s);
     }
 
+    while (DECAP_ENABLED && (*s == CHAR_FIXED_CASE || *s == CHAR_UNFIX_CASE))
+        s++;
+
     return s;
 }
 
diff --git a/gflib/string_util.h b/gflib/string_util.h
index 9e5dfffd57..75d2ada0a3 100644
--- a/gflib/string_util.h
+++ b/gflib/string_util.h
@@ -13,6 +13,7 @@ enum StringConvertMode
     STR_CONV_MODE_LEADING_ZEROS
 };
 
+bool32 IsStringAddrSafe(u8 *ptr, u32 length);
 u8 *StringCopy_Nickname(u8 *dest, const u8 *src);
 u8 *StringGet_Nickname(u8 *str);
 u8 *StringCopy_PlayerName(u8 *dest, const u8 *src);
diff --git a/gflib/text.c b/gflib/text.c
index bc917c7ced..139fd5ee1a 100644
--- a/gflib/text.c
+++ b/gflib/text.c
@@ -241,6 +241,35 @@ static void SetFontsPointer(const struct FontInfo *fonts)
     gFonts = fonts;
 }
 
+// Any ROM address must have bit 27 set (0x8000000)
+// so this is used to check if a pointer points to ROM
+#define IS_ROM_PTR(ptr) (((u32)ptr) >> 27)
+
+void * MirrorPtr(const void *ptr)
+{
+    if (IS_ROM_PTR(ptr)) // ROM
+        return ROM_MIRROR_PTR(ptr);
+    else // RAM
+        return RAM_MIRROR_PTR(ptr);
+}
+
+void * UnmirrorPtr(const void *ptr)
+{
+    u32 value = (u32) ptr;
+    if (IS_ROM_PTR(ptr)) // ROM
+        return (void*)(value & ~ROM_MIRROR_MASK);
+    else // RAM
+        return (void*)(value & ~RAM_MIRROR_MASK);
+}
+
+bool32 IsMirrorPtr(const void *ptr)
+{
+    if (IS_ROM_PTR(ptr))
+        return ((u32)ptr) & ROM_MIRROR_MASK;
+    else
+        return ((u32)ptr) & RAM_MIRROR_MASK;
+}
+
 void DeactivateAllTextPrinters(void)
 {
     int printer;
@@ -268,6 +297,11 @@ u16 AddTextPrinterParameterized(u8 windowId, u8 fontId, const u8 *str, u8 x, u8
     return AddTextPrinter(&printerTemplate, speed, callback);
 }
 
+u16 AddTextPrinterFixedCaseParameterized(u8 windowId, u8 fontId, const u8 *str, u8 x, u8 y, u8 speed, void (*callback)(struct TextPrinterTemplate *, u16))
+{
+    return AddTextPrinterParameterized(windowId, fontId, MirrorPtr(str), x, y, speed, callback);
+}
+
 bool16 AddTextPrinter(struct TextPrinterTemplate *printerTemplate, u8 speed, void (*callback)(struct TextPrinterTemplate *, u16))
 {
     int i;
@@ -281,6 +315,16 @@ bool16 AddTextPrinter(struct TextPrinterTemplate *printerTemplate, u8 speed, voi
     sTempTextPrinter.textSpeed = speed;
     sTempTextPrinter.delayCounter = 0;
     sTempTextPrinter.scrollDistance = 0;
+    if (DECAP_ENABLED)
+    {
+        // string address is mirrored; treat it as a fixed-case string
+        // Technically, unmirroring isn't necessary;
+        // but older emulators may not support mirroring
+        // printerTemplate->currentChar = UnmirrorPtr(printerTemplate->currentChar);
+        if (DECAP_MIRRORING && IsMirrorPtr(printerTemplate->currentChar))
+            sTempTextPrinter.lastChar = CHAR_FIXED_CASE;
+        sTempTextPrinter.lastChar = 0;
+    }
 
     for (i = 0; i < (int)ARRAY_COUNT(sTempTextPrinter.subStructFields); i++)
         sTempTextPrinter.subStructFields[i] = 0;
@@ -931,10 +975,30 @@ void DrawDownArrow(u8 windowId, u16 x, u16 y, u8 bgColor, bool8 drawArrow, u8 *c
     }
 }
 
+// if table[char] & 0xFF == 0, character is not uppercase
+const u16 gLowercaseDiffTable[] = {
+    // English
+    [CHAR_SPACE]                            = 0,
+    [CHAR_SPACER]                           = 0,
+    [CHAR_A ... CHAR_Z]                     = CHAR_a - CHAR_A,
+    // é treated as uppercase so POKéDEX, POKéMON, etc. decapped
+    [CHAR_e_ACUTE]                          = 0 | MARK_UPPER_FLAG,
+    [CHAR_SGL_QUOTE_RIGHT]                  = 0 | MARK_UPPER_FLAG,
+    // International
+    [CHAR_A_GRAVE ... CHAR_A_ACUTE]         = CHAR_a_GRAVE - CHAR_A_GRAVE,
+    [CHAR_A_CIRCUMFLEX]                     = CHAR_a_CIRCUMFLEX,
+    [CHAR_C_CEDILLA ... CHAR_I_GRAVE]       = CHAR_c_CEDILLA - CHAR_C_CEDILLA,
+    [CHAR_I_ACUTE]                          = CHAR_i_ACUTE,
+    [CHAR_I_CIRCUMFLEX ... CHAR_N_TILDE]    = CHAR_i_CIRCUMFLEX - CHAR_I_CIRCUMFLEX,
+    [CHAR_A_DIAERESIS ... CHAR_U_DIAERESIS] = CHAR_a_DIAERESIS - CHAR_A_DIAERESIS,
+    [EOS]                                   = 0,
+};
+
 static u16 RenderText(struct TextPrinter *textPrinter)
 {
     struct TextPrinterSubStruct *subStruct = (struct TextPrinterSubStruct *)(&textPrinter->subStructFields);
-    u16 currChar;
+    u32 currChar;
+    u32 lastChar;
     s32 width;
     s32 widthHelper;
 
@@ -962,6 +1026,12 @@ static u16 RenderText(struct TextPrinter *textPrinter)
 
         currChar = *textPrinter->printerTemplate.currentChar;
         textPrinter->printerTemplate.currentChar++;
+        if (DECAP_ENABLED)
+        {
+            lastChar = textPrinter->lastChar;
+            if (lastChar != CHAR_FIXED_CASE)
+                textPrinter->lastChar = currChar;
+        }
 
         switch (currChar)
         {
@@ -1117,7 +1187,47 @@ static u16 RenderText(struct TextPrinter *textPrinter)
             textPrinter->printerTemplate.currentX += gCurGlyph.width + textPrinter->printerTemplate.letterSpacing;
             return RENDER_PRINT;
         case EOS:
+            if (DECAP_ENABLED)
+                // Clear fixed case
+                textPrinter->lastChar = currChar;
             return RENDER_FINISH;
+    #if DECAP_ENABLED
+        // Disable/enable decapitalization
+        // In vanilla these are 1-2 pixel spaces
+        case CHAR_FIXED_CASE:
+        case CHAR_UNFIX_CASE:
+            textPrinter->lastChar = currChar;
+            if (!textPrinter->japanese)
+                return RENDER_REPEAT;
+            break;
+        // common decap exceptions
+        case CHAR_V:
+            if (lastChar == CHAR_T) // TV
+                lastChar = 0;
+            break;
+        case CHAR_M:
+            if (lastChar == CHAR_T) { // TM
+                lastChar = 0;
+                break;
+            }
+        case CHAR_P:
+            if (lastChar == CHAR_H) { // HP, HM
+                lastChar = 0;
+                break;
+            }
+        case CHAR_C:
+            if (lastChar == CHAR_P) // PC, PP, PM
+                lastChar = 0;
+            break;
+    #endif
+        }
+
+        // If not Japanese or fixed case, try to decap
+        if (DECAP_ENABLED && !textPrinter->japanese && lastChar != CHAR_FIXED_CASE)
+        {
+            // Two consecutive uppercase chars; lowercase this one
+            if (IS_UPPER(currChar) && IS_UPPER(lastChar))
+                currChar = TO_LOWER(currChar);
         }
 
         switch (subStruct->fontId)
diff --git a/gflib/text.h b/gflib/text.h
index ff13efa9a8..18af356f3d 100644
--- a/gflib/text.h
+++ b/gflib/text.h
@@ -7,6 +7,14 @@
 // loaded at once but not copied to vram yet.
 #define TEXT_SKIP_DRAW 0xFF
 
+// See include/config/decap.h for decap configuration
+#if DECAP_MIRRORING
+#define ROM_MIRROR_MASK (0x02000000)
+#define RAM_MIRROR_MASK (0x00800000)
+#define ROM_MIRROR_PTR(x) ((void*)(((u32)(x)) | ROM_MIRROR_MASK))
+#define RAM_MIRROR_PTR(x) ((void*)(((u32)(x)) | RAM_MIRROR_MASK))
+#endif
+
 enum {
     FONT_SMALL,
     FONT_NORMAL,
@@ -92,6 +100,7 @@ struct TextPrinter
     u8 scrollDistance;
     u8 minLetterSpacing;  // 0x20
     u8 japanese;
+    u8 lastChar; // used to determine whether to decap strings
 };
 
 struct FontInfo
@@ -135,6 +144,19 @@ extern TextFlags gTextFlags;
 extern u8 gDisableTextPrinters;
 extern struct TextGlyph gCurGlyph;
 
+extern const u16 gLowercaseDiffTable[];
+// in gLowercaseDiffTable, 0x100 represents a character treated as uppercase,
+// but that maps to itself; only the lower 8 bits are used for mapping
+#define MARK_UPPER_FLAG 0x100
+#define LOWERCASE_DIFF_MASK 0xFF
+#define IS_UPPER(x) (gLowercaseDiffTable[(x) & LOWERCASE_DIFF_MASK])
+#define TO_LOWER(x) (((x) + gLowercaseDiffTable[(x)]) & LOWERCASE_DIFF_MASK)
+
+void * UnmirrorPtr(const void * ptr);
+void * MirrorPtr(const void * ptr);
+bool32 IsMirrorPtr(const void *ptr);
+u16 AddTextPrinterFixedCaseParameterized(u8 windowId, u8 fontId, const u8 *str, u8 x, u8 y, u8 speed, void (*callback)(struct TextPrinterTemplate *, u16));
+
 void DeactivateAllTextPrinters(void);
 u16 AddTextPrinterParameterized(u8 windowId, u8 fontId, const u8 *str, u8 x, u8 y, u8 speed, void (*callback)(struct TextPrinterTemplate *, u16));
 bool16 AddTextPrinter(struct TextPrinterTemplate *template, u8 speed, void (*callback)(struct TextPrinterTemplate *, u16));
diff --git a/include/config/decap.h b/include/config/decap.h
new file mode 100644
index 0000000000..45755bbde9
--- /dev/null
+++ b/include/config/decap.h
@@ -0,0 +1,35 @@
+#ifndef GUARD_CONFIG_DECAP_H
+#define GUARD_CONFIG_DECAP_H
+
+/*
+Enable automatic decapitalization of *all* text
+Exceptions:
+- Several bigrams: TV, TM, HP, HM, PC, PP, PM
+- Player names, nicknames, box names
+- Strings beginning with {FIXED_CASE}
+- C strings that use `_C` or `__C`
+- ASM strings that use `.fixstr`
+- If mirroring enabled, string addresses passed through MirrorPtr
+*/
+#define DECAP_ENABLED TRUE
+// Enables signaling that a string's case should be preserved
+// by *mirroring* its address: i.e 08xxxxxx to 0Axxxxxx
+// Unless you are targeting a different platform than the GBA,
+// there aren't many reasons to disable this
+#define DECAP_MIRRORING TRUE
+
+// If TRUE, *all* Pokemon nicknames and player names will be decapitalized.
+// Otherwise, their case will be preserved. Default FALSE
+#define DECAP_NICKNAMES     FALSE
+
+#define DECAP_MAIN_MENU     TRUE // Main menu text.
+#define DECAP_OPTION_MENU   TRUE // Option menu text.
+#define DECAP_START_MENU    TRUE // Start menu options & Save menu text.
+#define DECAP_PARTY_MENU    TRUE // Party menu text.
+#define DECAP_MAP_NAMES     TRUE // Map and location names.
+#define DECAP_EASY_CHAT     TRUE // Easy Chat words and interface.
+#define DECAP_FIELD_MSG     TRUE // Field messages (including scripts!).
+#define DECAP_SUMMARY       TRUE // Summary interface text.
+#define DECAP_ITEM_NAMES    TRUE // Item names (obtained via ItemId_GetName).
+
+#endif // GUARD_CONFIG_DECAP_H
diff --git a/include/constants/global.h b/include/constants/global.h
index 6a2713c3d6..d2a72d235d 100644
--- a/include/constants/global.h
+++ b/include/constants/global.h
@@ -6,6 +6,7 @@
 #include "config/item.h"
 #include "config/pokemon.h"
 #include "config/overworld.h"
+#include "config/decap.h"
 
 // Invalid Versions show as "----------" in Gen 4 and Gen 5's summary screen.
 // In Gens 6 and 7, invalid versions instead show "a distant land" in the summary screen.
diff --git a/include/global.h b/include/global.h
index bb0786c86b..e9756df212 100644
--- a/include/global.h
+++ b/include/global.h
@@ -30,6 +30,9 @@
 // We define these when using certain IDEs to fool preproc
 #define _(x)        {x}
 #define __(x)       {x}
+// Like the above, but prepends a fixed-case character
+#define _C(x)       {x}
+#define __C(x)      {x}
 #define INCBIN(...) {0}
 #define INCBIN_U8   INCBIN
 #define INCBIN_U16  INCBIN
@@ -1073,4 +1076,6 @@ struct MapPosition
     s8 elevation;
 };
 
+extern u8 gStackBase[]; // Start of stack-allocated IWRAM
+
 #endif // GUARD_GLOBAL_H
diff --git a/ld_script.ld b/ld_script.ld
index e9cbae8957..f54272499c 100644
--- a/ld_script.ld
+++ b/ld_script.ld
@@ -56,6 +56,7 @@ SECTIONS {
         /* COMMON starts at 0x30022A8 */
         INCLUDE "sym_common.ld"
         *libc.a:sbrkr.o(COMMON);
+        gStackBase = .;
     } > IWRAM
 
     /* BEGIN ROM DATA */
diff --git a/ld_script_modern.ld b/ld_script_modern.ld
index fd35a1ca31..d5724ebf84 100644
--- a/ld_script_modern.ld
+++ b/ld_script_modern.ld
@@ -52,6 +52,7 @@ SECTIONS {
         gflib/*.o(COMMON);
         *libc.a:*.o(COMMON);
         *libnosys.a:*.o(COMMON);
+        gStackBase = .;
     } > IWRAM
 
     /* BEGIN ROM DATA */
diff --git a/ld_script_test.ld b/ld_script_test.ld
index ec99609a7e..e05971dfde 100644
--- a/ld_script_test.ld
+++ b/ld_script_test.ld
@@ -55,6 +55,7 @@ SECTIONS {
         data/*.o(COMMON);
         test/*.o(COMMON);
         *libc.a:sbrkr.o(COMMON);
+        gStackBase = .;
 
 	/* .persistent starts at 0x3007F00 */
 	/* WARNING: This is the end of the IRQ stack, if there's too
diff --git a/src/battle_message.c b/src/battle_message.c
index f2826c2b96..227b300f18 100644
--- a/src/battle_message.c
+++ b/src/battle_message.c
@@ -3204,6 +3204,13 @@ static const u8 *BattleStringGetPlayerName(u8 *text, u8 battler)
         break;
     }
 
+    if (DECAP_ENABLED && !DECAP_NICKNAMES && toCpy != text && *toCpy != CHAR_FIXED_CASE)
+    {
+        *text = CHAR_FIXED_CASE;
+        StringCopyN(text+1, toCpy, PLAYER_NAME_LENGTH);
+        toCpy = text;
+    }
+
     return toCpy;
 }
 
@@ -3260,7 +3267,7 @@ u32 BattleStringExpandPlaceholders(const u8 *src, u8 *dst)
         if (*src == PLACEHOLDER_BEGIN)
         {
             src++;
-            switch (*src)
+            switch (*src & ~PLACEHOLDER_FIXED_MASK)
             {
             case B_TXT_BUFF1:
                 if (gBattleTextBuff1[0] == B_BUFF_PLACEHOLDER_BEGIN)
@@ -3635,11 +3642,28 @@ u32 BattleStringExpandPlaceholders(const u8 *src, u8 *dst)
 
             if (toCpy != NULL)
             {
-                while (*toCpy != EOS)
+                if (DECAP_ENABLED)
                 {
-                    dst[dstID] = *toCpy;
-                    dstID++;
-                    toCpy++;
+                    bool32 fixedCase = *src & PLACEHOLDER_FIXED_MASK;
+
+                    if (fixedCase)
+                        dst[dstID++] = CHAR_FIXED_CASE;
+
+                    while (*toCpy != EOS)
+                    {
+                        if (*toCpy == CHAR_FIXED_CASE)
+                            fixedCase = TRUE;
+                        else if (*toCpy == CHAR_UNFIX_CASE)
+                            fixedCase = FALSE;
+                        dst[dstID++] = *toCpy++;
+                    }
+                    if (fixedCase)
+                        dst[dstID++] = CHAR_UNFIX_CASE;
+                }
+                else
+                {
+                    while (*toCpy != EOS)
+                        dst[dstID++] = *toCpy++;
                 }
             }
 
diff --git a/src/easy_chat.c b/src/easy_chat.c
index db5bbba8a8..7968efb17e 100644
--- a/src/easy_chat.c
+++ b/src/easy_chat.c
@@ -3954,6 +3954,8 @@ static void PrintTitle(void)
 
 static void PrintEasyChatText(u8 windowId, u8 fontId, const u8 *str, u8 x, u8 y, u8 speed, void (*callback)(struct TextPrinterTemplate *, u16))
 {
+    if (DECAP_ENABLED && DECAP_MIRRORING && !DECAP_EASY_CHAT)
+        str = MirrorPtr(str);
     AddTextPrinterParameterized(windowId, fontId, str, x, y, speed, callback);
 }
 
@@ -5240,6 +5242,9 @@ u8 *ConvertEasyChatWordsToString(u8 *dest, const u16 *src, u16 columns, u16 rows
     u16 i, j;
     u16 numColumns = columns - 1;
 
+    if (DECAP_ENABLED && !DECAP_EASY_CHAT)
+        *dest++ = CHAR_FIXED_CASE;
+
     for (i = 0; i < rows; i++)
     {
         for (j = 0; j < numColumns; j++)
diff --git a/src/field_message_box.c b/src/field_message_box.c
index b797e1d353..46f0f2898d 100755
--- a/src/field_message_box.c
+++ b/src/field_message_box.c
@@ -117,7 +117,15 @@ bool8 ShowFieldMessageFromBuffer(void)
 
 static void ExpandStringAndStartDrawFieldMessage(const u8 *str, bool32 allowSkippingDelayWithButtonPress)
 {
-    StringExpandPlaceholders(gStringVar4, str);
+    if (DECAP_ENABLED && DECAP_MIRRORING && !DECAP_FIELD_MSG)
+    {
+        gStringVar4[0] = CHAR_FIXED_CASE;
+        StringExpandPlaceholders(gStringVar4+1, str);
+    }
+    else
+    {
+        StringExpandPlaceholders(gStringVar4, str);
+    }
     AddTextPrinterForMessage(allowSkippingDelayWithButtonPress);
     CreateTask_DrawFieldMessage();
 }
diff --git a/src/fonts.c b/src/fonts.c
index 381fd795e9..72de054b73 100644
--- a/src/fonts.c
+++ b/src/fonts.c
@@ -9,7 +9,7 @@ ALIGNED(4) const u8 gFontSmallNarrowLatinGlyphWidths[] = {
     3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     5,  5,  3,  8,  8,  8,  8,  8,  8,  8,  4,  5,  4,  4,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  5,  3,  3,  3,  3,  3,  3,  4,
-    3,  3,  3,  3,  3,  3,  3,  5,  3,  8,  8,  8,  8,  1,  2,  3,
+    3,  3,  3,  3,  3,  3,  3,  5,  3,  8,  8,  8,  8,  0,  0,  3,
     4,  5,  6,  7,  5,  5,  5,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     7,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  4,  5,  3,  5,  5,
@@ -45,7 +45,7 @@ ALIGNED(4) const u8 gFontSmallLatinGlyphWidths[] = {
     3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     5,  5,  5,  8,  8,  8,  8,  8,  8,  8,  4,  7,  5,  5,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  5,  3,  3,  3,  3,  3,  3,  4,
-    3,  3,  3,  3,  3,  3,  3,  5,  3,  8,  8,  8,  8,  1,  2,  3,
+    3,  3,  3,  3,  3,  3,  3,  5,  3,  8,  8,  8,  8,  0,  0,  3,
     4,  5,  6,  7,  5,  7,  7,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     8,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  4,  5,  5,  5,  5,
@@ -81,7 +81,7 @@ ALIGNED(4) const u8 gFontNarrowLatinGlyphWidths[] = {
     3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     5,  5,  4,  8,  8,  8,  7,  8,  8,  4,  4,  6,  4,  4,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  5,  3,  3,  3,  3,  3,  3,  4,
-    3,  3,  3,  3,  3,  3,  3,  5,  3,  7,  7,  7,  7,  1,  2,  3,
+    3,  3,  3,  3,  3,  3,  3,  5,  3,  7,  7,  7,  7,  0,  0,  3,
     4,  5,  6,  7,  5,  6,  6,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     8,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  4,  5,  3,  5,  3,
@@ -117,7 +117,7 @@ ALIGNED(4) const u8 gFontShortLatinGlyphWidths[] = {
     3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     6,  6,  6,  8,  8,  8,  8,  8,  8,  4,  6,  8,  5,  5,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  6,  3,  3,  3,  3,  3,  3,  6,
-    3,  3,  3,  3,  3,  3,  3,  6,  3, 12, 12, 12, 12,  1,  2,  3,
+    3,  3,  3,  3,  3,  3,  3,  6,  3, 12, 12, 12, 12,  0,  0,  3,
     4,  5,  6,  7,  8,  8,  8,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     8,  6,  6,  6,  6,  6,  6,  6,  6,  6,  6,  6,  6,  5,  6,  5,
@@ -153,7 +153,7 @@ ALIGNED(4) const u8 gFontNormalLatinGlyphWidths[] = {
     3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     6,  6,  4,  8,  8,  8,  7,  8,  8,  4,  6,  6,  4,  4,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  6,  3,  3,  3,  3,  3,  3,  6,
-    3,  3,  3,  3,  3,  3,  3,  6,  3,  7,  7,  7,  7,  1,  2,  3,
+    3,  3,  3,  3,  3,  3,  3,  6,  3,  7,  7,  7,  7,  0,  0,  3,
     4,  5,  6,  7,  6,  6,  6,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     8,  6,  6,  6,  6,  6,  6,  6,  6,  6,  6,  4,  6,  3,  6,  3,
diff --git a/src/item.c b/src/item.c
index e102af7266..4e4e78345a 100644
--- a/src/item.c
+++ b/src/item.c
@@ -866,7 +866,10 @@ static u16 SanitizeItemId(u16 itemId)
 
 const u8 *ItemId_GetName(u16 itemId)
 {
-    return gItems[SanitizeItemId(itemId)].name;
+    if (DECAP_ENABLED && DECAP_MIRRORING && !DECAP_ITEM_NAMES)
+        return ROM_MIRROR_PTR(gItems[SanitizeItemId(itemId)].name);
+    else
+        return gItems[SanitizeItemId(itemId)].name;
 }
 
 u32 ItemId_GetPrice(u16 itemId)
diff --git a/src/main.c b/src/main.c
index 19b8f19976..c56c796eac 100644
--- a/src/main.c
+++ b/src/main.c
@@ -95,7 +95,14 @@ void AgbMain()
 {
     *(vu16 *)BG_PLTT = RGB_WHITE; // Set the backdrop to white on startup
     InitGpuRegManager();
-    REG_WAITCNT = WAITCNT_PREFETCH_ENABLE | WAITCNT_WS0_S_1 | WAITCNT_WS0_N_3;
+    // Setup waitstates for all ROM mirrors
+    if (DECAP_ENABLED && DECAP_MIRRORING)
+        REG_WAITCNT = WAITCNT_PREFETCH_ENABLE
+            | WAITCNT_WS0_S_1 | WAITCNT_WS0_N_3
+            | WAITCNT_WS1_S_1 | WAITCNT_WS1_N_3
+            | WAITCNT_WS2_S_1 | WAITCNT_WS2_N_3;
+    else
+        REG_WAITCNT = WAITCNT_PREFETCH_ENABLE | WAITCNT_WS0_S_1 | WAITCNT_WS0_N_3;
     InitKeys();
     InitIntrHandlers();
     m4aSoundInit();
diff --git a/src/main_menu.c b/src/main_menu.c
index c1f092b2ca..6a225bf97d 100644
--- a/src/main_menu.c
+++ b/src/main_menu.c
@@ -163,6 +163,11 @@
  *  - Destroys itself when done.
  */
 
+#if (DECAP_ENABLED) && (DECAP_MIRRORING) && !(DECAP_MAIN_MENU)
+#define AddTextPrinterParameterized3(a, b, c, d, e, f, str) AddTextPrinterParameterized3(a, b, c, d, e, f, MirrorPtr(str))
+#endif
+
+
 #define OPTION_MENU_FLAG (1 << 15)
 
 // Static type declarations
diff --git a/src/naming_screen.c b/src/naming_screen.c
index 0f2e2dbb7f..848e5b1a48 100644
--- a/src/naming_screen.c
+++ b/src/naming_screen.c
@@ -1856,7 +1856,18 @@ static void SaveInputText(void)
     {
         if (sNamingScreen->textBuffer[i] != CHAR_SPACE && sNamingScreen->textBuffer[i] != EOS)
         {
-            StringCopyN(sNamingScreen->destBuffer, sNamingScreen->textBuffer, sNamingScreen->template->maxChars + 1);
+            // If there is space, prepend fixed-case character
+            if (DECAP_ENABLED && !DECAP_NICKNAMES
+             && (sNamingScreen->templateNum == NAMING_SCREEN_PLAYER
+                || sNamingScreen->templateNum == NAMING_SCREEN_NICKNAME
+                || sNamingScreen->templateNum == NAMING_SCREEN_CAUGHT_MON)
+             && sNamingScreen->textBuffer[GetTextEntryPosition()] == EOS)
+            {
+                *sNamingScreen->destBuffer = CHAR_FIXED_CASE;
+                StringCopyN(sNamingScreen->destBuffer + 1, sNamingScreen->textBuffer, sNamingScreen->template->maxChars + 0);
+            }
+            else
+                StringCopyN(sNamingScreen->destBuffer, sNamingScreen->textBuffer, sNamingScreen->template->maxChars + 1);
             break;
         }
     }
@@ -2584,5 +2595,3 @@ static const struct SpritePalette sSpritePalettes[] =
     {gNamingScreenMenu_Pal[4], PALTAG_OK_BUTTON},
     {}
 };
-
-
diff --git a/src/option_menu.c b/src/option_menu.c
index 67169b1f9b..af10b75a20 100644
--- a/src/option_menu.c
+++ b/src/option_menu.c
@@ -24,6 +24,11 @@
 #define tButtonMode data[5]
 #define tWindowFrameType data[6]
 
+#if (DECAP_ENABLED) && (DECAP_MIRRORING) && !(DECAP_OPTION_MENU)
+#define AddTextPrinterParameterized3(a, b, c, d, e, f, str) AddTextPrinterParameterized3(a, b, c, d, e, f, MirrorPtr(str))
+#define AddTextPrinterParameterized4(a, b, c, d, e, f, g, h, str) AddTextPrinterParameterized4(a, b, c, d, e, f, g, h, MirrorPtr(str))
+#endif
+
 enum
 {
     MENUITEM_TEXTSPEED,
diff --git a/src/party_menu.c b/src/party_menu.c
index 07e4b405ff..57a4234183 100644
--- a/src/party_menu.c
+++ b/src/party_menu.c
@@ -75,6 +75,12 @@
 #include "constants/rgb.h"
 #include "constants/songs.h"
 
+#if (DECAP_ENABLED) && (DECAP_MIRRORING) && !(DECAP_PARTY_MENU)
+#define gStringVar4 (MirrorPtr(gStringVar4))
+#define AddTextPrinterParameterized4(a, b, c, d, e, f, g, h, str) (AddTextPrinterParameterized4(a, b, c, d, e, f, g, h, MirrorPtr(str)))
+#define AddTextPrinterParameterized3(a, b, c, d, e, f, str) AddTextPrinterParameterized3(a, b, c, d, e, f, MirrorPtr(str))
+#endif
+
 enum {
     MENU_SUMMARY,
     MENU_SWITCH,
@@ -2740,7 +2746,10 @@ static void PrintMessage(const u8 *text)
 {
     DrawStdFrameWithCustomTileAndPalette(WIN_MSG, FALSE, 0x4F, 13);
     gTextFlags.canABSpeedUpPrint = TRUE;
-    AddTextPrinterParameterized2(WIN_MSG, FONT_NORMAL, text, GetPlayerTextSpeedDelay(), 0, TEXT_COLOR_DARK_GRAY, TEXT_COLOR_WHITE, TEXT_COLOR_LIGHT_GRAY);
+    if (DECAP_ENABLED && DECAP_MIRRORING && !DECAP_PARTY_MENU)
+        AddTextPrinterParameterized2(WIN_MSG, FONT_NORMAL, MirrorPtr(text), GetPlayerTextSpeedDelay(), 0, TEXT_COLOR_DARK_GRAY, TEXT_COLOR_WHITE, TEXT_COLOR_LIGHT_GRAY);
+    else
+        AddTextPrinterParameterized2(WIN_MSG, FONT_NORMAL, text, GetPlayerTextSpeedDelay(), 0, TEXT_COLOR_DARK_GRAY, TEXT_COLOR_WHITE, TEXT_COLOR_LIGHT_GRAY);
 }
 
 static void PartyMenuDisplayYesNoMenu(void)
diff --git a/src/pokemon.c b/src/pokemon.c
index 7a77ea9c17..0c445ab307 100644
--- a/src/pokemon.c
+++ b/src/pokemon.c
@@ -2153,6 +2153,8 @@ u32 GetBoxMonData3(struct BoxPokemon *boxMon, s32 field, u8 *data)
             }
             else
             {
+                if (DECAP_ENABLED && !DECAP_NICKNAMES && IsStringAddrSafe(data, POKEMON_NAME_LENGTH))
+                        *data++ = CHAR_FIXED_CASE;
                 retVal = 0;
                 while (retVal < min(sizeof(boxMon->nickname), POKEMON_NAME_LENGTH))
                 {
@@ -2515,6 +2517,8 @@ u32 GetBoxMonData3(struct BoxPokemon *boxMon, s32 field, u8 *data)
             break;
         case MON_DATA_OT_NAME:
         {
+            if (DECAP_ENABLED && !DECAP_NICKNAMES && IsStringAddrSafe(data, PLAYER_NAME_LENGTH))
+                *data++ = CHAR_FIXED_CASE;
             retVal = 0;
 
             while (retVal < PLAYER_NAME_LENGTH)
diff --git a/src/pokemon_storage_system.c b/src/pokemon_storage_system.c
index fcf66ccea8..2fa88b4db5 100644
--- a/src/pokemon_storage_system.c
+++ b/src/pokemon_storage_system.c
@@ -5548,7 +5548,10 @@ static void InitBoxTitle(u8 boxId)
     sStorage->wallpaperPalBits |= (1 << 16) << tagIndex;
 
     StringCopyPadded(sStorage->boxTitleText, GetBoxNamePtr(boxId), 0, BOX_NAME_LENGTH);
-    DrawTextWindowAndBufferTiles(sStorage->boxTitleText, sStorage->boxTitleTiles, 0, 0, 2);
+    if (DECAP_ENABLED && DECAP_MIRRORING)
+        DrawTextWindowAndBufferTiles(MirrorPtr(sStorage->boxTitleText), sStorage->boxTitleTiles, 0, 0, 2);
+    else
+        DrawTextWindowAndBufferTiles(sStorage->boxTitleText, sStorage->boxTitleTiles, 0, 0, 2);
     LoadSpriteSheet(&spriteSheet);
     x = GetBoxTitleBaseX(GetBoxNamePtr(boxId));
 
@@ -9606,7 +9609,10 @@ struct BoxPokemon *GetBoxedMonPtr(u8 boxId, u8 boxPosition)
 u8 *GetBoxNamePtr(u8 boxId)
 {
     if (boxId < TOTAL_BOXES_COUNT)
-        return gPokemonStoragePtr->boxNames[boxId];
+        if (DECAP_ENABLED && DECAP_MIRRORING)
+            return MirrorPtr(gPokemonStoragePtr->boxNames[boxId]);
+        else
+            return gPokemonStoragePtr->boxNames[boxId];
     else
         return NULL;
 }
diff --git a/src/pokemon_summary_screen.c b/src/pokemon_summary_screen.c
index 41c4f9f76d..64122472bb 100644
--- a/src/pokemon_summary_screen.c
+++ b/src/pokemon_summary_screen.c
@@ -2819,7 +2819,10 @@ static void ResetWindows(void)
 
 static void PrintTextOnWindow(u8 windowId, const u8 *string, u8 x, u8 y, u8 lineSpacing, u8 colorId)
 {
-    AddTextPrinterParameterized4(windowId, FONT_NORMAL, x, y, 0, lineSpacing, sTextColors[colorId], 0, string);
+    if (DECAP_ENABLED && DECAP_MIRRORING && !DECAP_SUMMARY)
+        AddTextPrinterParameterized4(windowId, FONT_NORMAL, x, y, 0, lineSpacing, sTextColors[colorId], 0, MirrorPtr(string));
+    else
+        AddTextPrinterParameterized4(windowId, FONT_NORMAL, x, y, 0, lineSpacing, sTextColors[colorId], 0, string);
 }
 
 static void PrintMonInfo(void)
diff --git a/src/region_map.c b/src/region_map.c
index 8936e668ac..36c6ae8fc6 100644
--- a/src/region_map.c
+++ b/src/region_map.c
@@ -1570,6 +1570,9 @@ u8 *GetMapName(u8 *dest, u16 regionMapId, u16 padLength)
     u8 *str;
     u16 i;
 
+    if (DECAP_ENABLED && !DECAP_MAP_NAMES)
+        *dest++ = CHAR_FIXED_CASE;
+
     if (regionMapId == MAPSEC_SECRET_BASE)
     {
         str = GetSecretBaseMapName(dest);
diff --git a/src/start_menu.c b/src/start_menu.c
index 0525ccf70d..857eed168d 100644
--- a/src/start_menu.c
+++ b/src/start_menu.c
@@ -48,6 +48,10 @@
 #include "constants/rgb.h"
 #include "constants/songs.h"
 
+#if (DECAP_ENABLED) && (DECAP_MIRRORING) && !(DECAP_START_MENU)
+#define AddTextPrinterParameterized (AddTextPrinterFixedCaseParameterized)
+#endif
+
 // Menu actions
 enum
 {
diff --git a/src/strings.c b/src/strings.c
index 565f0a8f62..35f610017a 100644
--- a/src/strings.c
+++ b/src/strings.c
@@ -2,6 +2,7 @@
 #include "strings.h"
 #include "battle_pyramid_bag.h"
 #include "item_menu.h"
+#include "text.h"
 
 ALIGNED(4)
 const u8 gText_ExpandedPlaceholder_Empty[] = _("");
@@ -173,7 +174,7 @@ const u8 gText_Number[] = _("No. ");
 const u8 gText_Level[] = _("Lv. ");
 const u8 gText_IdNumberSlash[] = _("IDNo. /"); // Unused
 const u8 gText_Name[] = _("NAME");
-const u8 gText_IDNumber[] = _("IDNo.");
+const u8 gText_IDNumber[] = _C("IDNo.");
 const u8 gText_BirchInTrouble[] = _("PROF. BIRCH is in trouble!\nRelease a POKéMON and rescue him!");
 const u8 gText_ConfirmStarterChoice[] = _("Do you choose this POKéMON?");
 const u8 gText_Pokemon4[] = _("POKéMON"); // Unused
@@ -500,7 +501,7 @@ const u8 gText_SpDef4[] = _("SP. DEF");
 const u8 gText_Speed2[] = _("SPEED");
 const u8 gText_HP4[] = _("HP");
 const u8 gText_EmptyString8[] = _(""); // Unused
-const u8 gText_OTSlash[] = _("OT/");
+const u8 gText_OTSlash[] = _C("OT/");
 const u8 gText_RentalPkmn[] = _("RENTAL POKéMON");
 const u8 gText_TypeSlash[] = _("TYPE/");
 const u8 gText_Power[] = _("POWER");
@@ -517,7 +518,7 @@ const u8 gText_Switch[] = _("SWITCH");
 const u8 gText_PkmnInfo[] = _("POKéMON INFO");
 const u8 gText_PkmnSkills[] = _("POKéMON SKILLS");
 const u8 gText_BattleMoves[] = _("BATTLE MOVES");
-const u8 gText_ContestMoves[] = _("C0NTEST MOVES");
+const u8 gText_ContestMoves[] = _("CONTEST MOVES");
 const u8 gText_Info[] = _("INFO");
 const u8 gText_EggWillTakeALongTime[] = _("It looks like this EGG will\ntake a long time to hatch.");
 const u8 gText_EggWillTakeSomeTime[] = _("What will hatch from this?\nIt will take some time.");
@@ -1103,9 +1104,15 @@ const u8 gText_GamePlayCannotBeContinued[] = _("{COLOR RED}“Game play cannot b
 const u8 gText_CheckCompleted[] = _("Check completed.\nAttempting to save again.\nPlease wait.");
 const u8 gText_SaveCompleteGameCannotContinue[] = _("Save completed.\n{COLOR RED}“Game play cannot be continued.\nReturning to the title screen.”");
 const u8 gText_SaveCompletePressA[] = _("Save completed.\n{COLOR RED}“Please press the A Button.”");
+#if (DECAP_ENABLED) && !(DECAP_MAP_NAMES)
+const u8 gText_Ferry[] = _C("FERRY");
+const u8 gText_SecretBase[] = _C("SECRET BASE");
+const u8 gText_Hideout[] = _C("HIDEOUT");
+#else
 const u8 gText_Ferry[] = _("FERRY");
 const u8 gText_SecretBase[] = _("SECRET BASE");
 const u8 gText_Hideout[] = _("HIDEOUT");
+#endif
 const u8 gText_ResetRTCConfirmCancel[] = _("Reset RTC?\nA: Confirm, B: Cancel");
 const u8 gText_PresentTime[] = _("Present time in game");
 const u8 gText_PreviousTime[] = _("Previous time in game");
@@ -1203,7 +1210,7 @@ const u8 gText_PkmnFainted_FldPsn[] = _("{STR_VAR_1} survived the poisoning.\nTh
 #endif
 const u8 gText_Marco[] = _("MARCO");
 const u8 gText_TrainerCardName[] = _("NAME: ");
-const u8 gText_TrainerCardIDNo[] = _("IDNo.");
+const u8 gText_TrainerCardIDNo[] = _C("IDNo.");
 const u8 gText_TrainerCardMoney[] = _("MONEY");
 const u8 gText_PokeDollar[] = _("¥"); // Unused
 const u8 gText_TrainerCardPokedex[] = _("POKéDEX");
diff --git a/test/test_runner_battle.c b/test/test_runner_battle.c
index caccdb2042..043e93b427 100644
--- a/test/test_runner_battle.c
+++ b/test/test_runner_battle.c
@@ -12,6 +12,7 @@
 #include "random.h"
 #include "test/battle.h"
 #include "window.h"
+#include "text.h"
 #include "constants/trainers.h"
 
 #if defined(__INTELLISENSE__)
@@ -1185,6 +1186,13 @@ static s32 TryMessage(s32 i, s32 n, const u8 *string)
                 if (string[j] == CHAR_PROMPT_CLEAR)
                     j++;
             }
+            if (DECAP_ENABLED && (string[j] == CHAR_FIXED_CASE || string[j] == CHAR_UNFIX_CASE))
+            {
+                // Ignores case-fixing characters in string
+                // k will be incremented in 'continue'
+                k--;
+                continue;
+            }
             if (string[j] != event->pattern[k])
             {
                 break;
diff --git a/tools/preproc/asm_file.cpp b/tools/preproc/asm_file.cpp
index 04a7410e00..95655f6ac9 100644
--- a/tools/preproc/asm_file.cpp
+++ b/tools/preproc/asm_file.cpp
@@ -170,6 +170,8 @@ Directive AsmFile::GetDirective()
 
     if (CheckForDirective(".include"))
         return Directive::Include;
+    else if (CheckForDirective(".fixstr"))
+        return Directive::FixedString;
     else if (CheckForDirective(".string"))
         return Directive::String;
     else if (CheckForDirective(".braille"))
diff --git a/tools/preproc/asm_file.h b/tools/preproc/asm_file.h
index 29435f76a4..9659c7264f 100644
--- a/tools/preproc/asm_file.h
+++ b/tools/preproc/asm_file.h
@@ -31,6 +31,7 @@ enum class Directive
     Include,
     String,
     Braille,
+    FixedString,
     Unknown
 };
 
diff --git a/tools/preproc/c_file.cpp b/tools/preproc/c_file.cpp
index 508c628731..d400a75d04 100644
--- a/tools/preproc/c_file.cpp
+++ b/tools/preproc/c_file.cpp
@@ -195,6 +195,7 @@ void CFile::TryConvertString()
     long oldPos = m_pos;
     long oldLineNum = m_lineNum;
     bool noTerminator = false;
+    bool fixedCase = false;
 
     if (m_buffer[m_pos] != '_' || (m_pos > 0 && IsIdentifierChar(m_buffer[m_pos - 1])))
         return;
@@ -207,6 +208,13 @@ void CFile::TryConvertString()
         m_pos++;
     }
 
+    // Fixed-case string
+    if (m_buffer[m_pos] == 'C')
+    {
+        fixedCase = true;
+        m_pos++;
+    }
+
     SkipWhitespace();
 
     if (m_buffer[m_pos] != '(')
@@ -234,7 +242,13 @@ void CFile::TryConvertString()
 
             try
             {
-                m_pos += stringParser.ParseString(m_pos, s, length);
+                if (fixedCase) {
+                    s[0] = '\x7d'; // FIXED_CASE
+                    m_pos += stringParser.ParseString(m_pos, s+1, length);
+                    length++;
+                } else {
+                    m_pos += stringParser.ParseString(m_pos, s, length);
+                }
             }
             catch (std::runtime_error& e)
             {
diff --git a/tools/preproc/preproc.cpp b/tools/preproc/preproc.cpp
index eb2d4c8a23..554482dfb1 100644
--- a/tools/preproc/preproc.cpp
+++ b/tools/preproc/preproc.cpp
@@ -76,6 +76,16 @@ void PreprocAsmFile(std::string filename)
             PrintAsmBytes(s, length);
             break;
         }
+        // Like String, but prepends FIXED_CASE char
+        case Directive::FixedString:
+        {
+            unsigned char s[kMaxStringLength];
+            int length = 0;
+            s[length++] = '\x7d'; // FIXED_CASE
+            length += stack.top().ReadString(s+length);
+            PrintAsmBytes(s, length);
+            break;
+        }
         case Directive::Braille:
         {
             unsigned char s[kMaxStringLength];