diff --git a/asm/code_08030C94.s b/asm/code_08030C94.s
index 5100006..9c78073 100644
--- a/asm/code_08030C94.s
+++ b/asm/code_08030C94.s
@@ -997,7 +997,7 @@ _080314C4:
 	ldr r0, [r4, #0xc]
 	cmp r0, #0
 	bne _080315AE
-	ldr r1, _080314EC @ =gUnk_03002554
+	ldr r1, _080314EC @ =gMultiSioStatusFlags
 	ldr r2, [r1]
 	movs r0, #0x80
 	lsls r0, r0, #5
@@ -1012,7 +1012,7 @@ _080314C4:
 	b _08031524
 	.align 2, 0
 _080314E8: .4byte gUnk_020382A0
-_080314EC: .4byte gUnk_03002554
+_080314EC: .4byte gMultiSioStatusFlags
 _080314F0: .4byte 0x0000FFFE
 _080314F4:
 	movs r1, #0x80
@@ -1161,7 +1161,7 @@ _08031600:
 	movs r1, #0x80
 	lsls r1, r1, #1
 	lsls r1, r3
-	ldr r0, _08031638 @ =gUnk_03002554
+	ldr r0, _08031638 @ =gMultiSioStatusFlags
 	ldr r2, [r0]
 	ands r1, r2
 	cmp r1, #0
@@ -1186,7 +1186,7 @@ _08031600:
 	mov sb, r0
 	b _0803167C
 	.align 2, 0
-_08031638: .4byte gUnk_03002554
+_08031638: .4byte gMultiSioStatusFlags
 _0803163C: .4byte gMultiSioRecv
 _08031640: .4byte 0x0000FFFB
 _08031644:
@@ -1267,7 +1267,7 @@ sub_0803169C: @ 0x0803169C
 	ands r0, r1
 	cmp r0, #0
 	bne _0803171C
-	ldr r0, _08031714 @ =gUnk_03002554
+	ldr r0, _08031714 @ =gMultiSioStatusFlags
 	ldr r2, [r0]
 	movs r0, #0x80
 	ands r0, r2
@@ -1293,7 +1293,7 @@ _08031704: .4byte gMultiSioSend
 _08031708: .4byte 0x00000123
 _0803170C: .4byte 0x0000FFFC
 _08031710: .4byte 0x04000128
-_08031714: .4byte gUnk_03002554
+_08031714: .4byte gMultiSioStatusFlags
 _08031718: .4byte sub_08031764
 _0803171C:
 	ldr r3, _08031758 @ =0x04000128
@@ -1302,7 +1302,7 @@ _0803171C:
 	ands r0, r1
 	cmp r0, #0
 	beq _08031750
-	ldr r0, _0803175C @ =gUnk_03002554
+	ldr r0, _0803175C @ =gMultiSioStatusFlags
 	ldr r2, [r0]
 	movs r0, #0x80
 	ands r0, r2
@@ -1330,7 +1330,7 @@ _08031750:
 	bx r1
 	.align 2, 0
 _08031758: .4byte 0x04000128
-_0803175C: .4byte gUnk_03002554
+_0803175C: .4byte gMultiSioStatusFlags
 _08031760: .4byte sub_080319F0
 
 	thumb_func_start sub_08031764
@@ -1355,7 +1355,7 @@ sub_08031764: @ 0x08031764
 	ands r0, r1
 	cmp r0, #0
 	bne _080317A8
-	ldr r0, _080317CC @ =gUnk_03002554
+	ldr r0, _080317CC @ =gMultiSioStatusFlags
 	ldr r2, [r0]
 	movs r0, #0x80
 	ands r0, r2
@@ -1384,7 +1384,7 @@ _080317BC: .4byte gUnk_020382A0
 _080317C0: .4byte gMultiSioSend
 _080317C4: .4byte 0x00000123
 _080317C8: .4byte 0x04000128
-_080317CC: .4byte gUnk_03002554
+_080317CC: .4byte gMultiSioStatusFlags
 _080317D0: .4byte 0x0000FFFC
 _080317D4: .4byte sub_0803169C
 _080317D8:
@@ -1489,7 +1489,7 @@ sub_08031860: @ 0x08031860
 	ands r0, r1
 	cmp r0, #0
 	bne _080318B8
-	ldr r1, _080318DC @ =gUnk_03002554
+	ldr r1, _080318DC @ =gMultiSioStatusFlags
 	ldr r2, [r1]
 	movs r0, #0x80
 	ands r0, r2
@@ -1519,7 +1519,7 @@ _080318CC: .4byte gUnk_020382A0
 _080318D0: .4byte gMultiSioSend
 _080318D4: .4byte 0x00000123
 _080318D8: .4byte 0x04000128
-_080318DC: .4byte gUnk_03002554
+_080318DC: .4byte gMultiSioStatusFlags
 _080318E0: .4byte 0x0000FFFC
 _080318E4: .4byte sub_0803169C
 _080318E8:
@@ -1687,7 +1687,7 @@ sub_080319F0: @ 0x080319F0
 	ands r0, r1
 	cmp r0, #0
 	beq _08031A38
-	ldr r0, _08031A60 @ =gUnk_03002554
+	ldr r0, _08031A60 @ =gMultiSioStatusFlags
 	ldr r2, [r0]
 	movs r0, #0x80
 	ands r0, r2
@@ -1718,7 +1718,7 @@ _08031A50: .4byte gMultiSioSend
 _08031A54: .4byte gMultiSioRecv
 _08031A58: .4byte 0x00000123
 _08031A5C: .4byte 0x04000128
-_08031A60: .4byte gUnk_03002554
+_08031A60: .4byte gMultiSioStatusFlags
 _08031A64: .4byte 0x0000FFFC
 _08031A68: .4byte sub_0803169C
 _08031A6C:
@@ -1779,7 +1779,7 @@ sub_08031AA8: @ 0x08031AA8
 	ands r0, r1
 	cmp r0, #0
 	beq _08031AF4
-	ldr r0, _08031B1C @ =gUnk_03002554
+	ldr r0, _08031B1C @ =gMultiSioStatusFlags
 	ldr r2, [r0]
 	movs r0, #0x80
 	ands r0, r2
@@ -1810,7 +1810,7 @@ _08031B0C: .4byte gMultiSioSend
 _08031B10: .4byte gMultiSioRecv
 _08031B14: .4byte 0x00000123
 _08031B18: .4byte 0x04000128
-_08031B1C: .4byte gUnk_03002554
+_08031B1C: .4byte gMultiSioStatusFlags
 _08031B20: .4byte 0x0000FFFC
 _08031B24: .4byte sub_0803169C
 _08031B28:
@@ -4466,7 +4466,7 @@ _08032F6E:
 	ldr r0, [r1, #8]
 	movs r2, #0x80
 	lsls r2, r2, #0x18
-	ldr r3, _08032FF4 @ =gUnk_03002554
+	ldr r3, _08032FF4 @ =gMultiSioStatusFlags
 	ldr r5, _08032FF8 @ =gUnk_03002558
 	cmp r0, #0
 	bge _08032F98
@@ -4514,7 +4514,7 @@ _08032FE4: .4byte gMultiSioSend
 _08032FE8: .4byte 0x85000005
 _08032FEC: .4byte gMultiSioRecv
 _08032FF0: .4byte 0x85000014
-_08032FF4: .4byte gUnk_03002554
+_08032FF4: .4byte gMultiSioStatusFlags
 _08032FF8: .4byte gUnk_03002558
 _08032FFC: .4byte 0x04000208
 _08033000: .4byte gIntrTable
diff --git a/asm/code_0815819C.s b/asm/code_0815819C.s
index eae7c23..a04ac16 100644
--- a/asm/code_0815819C.s
+++ b/asm/code_0815819C.s
@@ -1027,7 +1027,7 @@ sub_08158934: @ 0x08158934
 	ldr r1, _08158980 @ =0x85000014
 	str r1, [r0, #8]
 	ldr r0, [r0, #8]
-	ldr r0, _08158984 @ =gUnk_03002554
+	ldr r0, _08158984 @ =gMultiSioStatusFlags
 	str r2, [r0]
 	ldr r0, _08158988 @ =gUnk_03002558
 	strb r2, [r0]
@@ -1042,7 +1042,7 @@ _08158974: .4byte gMultiSioSend
 _08158978: .4byte 0x85000005
 _0815897C: .4byte gMultiSioRecv
 _08158980: .4byte 0x85000014
-_08158984: .4byte gUnk_03002554
+_08158984: .4byte gMultiSioStatusFlags
 _08158988: .4byte gUnk_03002558
 
 	thumb_func_start sub_0815898C
diff --git a/include/main.h b/include/main.h
index 5a5ceec..053b0cf 100644
--- a/include/main.h
+++ b/include/main.h
@@ -81,7 +81,7 @@ extern u16 gUnk_03002544;
 extern u8 gUnk_03002548;
 extern u16 gUnk_0300254C;
 extern u8 gUnk_03002550;
-extern u32 gUnk_03002554;
+extern u32 gMultiSioStatusFlags;
 extern u8 gUnk_03002558;
 extern u8 gUnk_03002760[2][0x280];
 extern u16 gObjPalette[0x100];
diff --git a/include/multi_08019F28.h b/include/multi_08019F28.h
index 73bcfcf..3b77c78 100644
--- a/include/multi_08019F28.h
+++ b/include/multi_08019F28.h
@@ -28,7 +28,7 @@ struct Multi_08019F28
     u16 unk9E;
     u8 fillerA0[4];
     s32 unkA4;
-    u8 unkA8;
+    u8 loadRequest;
     u8 unkA9;
     u16 unkAA;
     u16 unkAC;
diff --git a/include/multi_sio.h b/include/multi_sio.h
index 21bf896..3dab688 100644
--- a/include/multi_sio.h
+++ b/include/multi_sio.h
@@ -180,38 +180,44 @@ extern u32 MultiSioMain(void *sendp, void *recvp, u32 loadRequest);
 
 //* Return Value:
 
-#define MULTI_SIO_RECV_ID_MASK      0x000f  // Receive Success Flag
-#define MULTI_SIO_CONNECTED_ID_MASK 0x0f00  // Connection History Flag
+#define MULTI_SIO_RECV_ID_MASK          0x000f  // Receive success flag
+#define MULTI_SIO_CONNECTED_ID_MASK     0x0f00  // Connection history flag
 
-#define MULTI_SIO_RECV_ID0          0x0001  // Receive Success Flag Master
-#define MULTI_SIO_RECV_ID1          0x0002  //                Slave 1
-#define MULTI_SIO_RECV_ID2          0x0004  //                Slave 2
-#define MULTI_SIO_RECV_ID3          0x0008  //                Slave 3
-#define MULTI_SIO_LD_ENABLE         0x0010  // Enable Load
-#define MULTI_SIO_LD_REQUEST        0x0020  // Load Request
-#define MULTI_SIO_LD_SUCCESS        0x0040  // Load Success
-#define MULTI_SIO_TYPE              0x0080  // Connection (Master/Slave)
-#define MULTI_SIO_PARENT            0x0080  // Master Connection
-#define MULTI_SIO_CHILD             0x0000  // Slave Connection
-#define MULTI_SIO_CONNECTED_ID0     0x0100  // Connection History Flag Master
-#define MULTI_SIO_CONNECTED_ID1     0x0200  //                Slave 1
-#define MULTI_SIO_CONNECTED_ID2     0x0400  //                Slave 2
-#define MULTI_SIO_CONNECTED_ID3     0x0800  //                Slave 3
-#define MULTI_SIO_UNK_x1000         0x1000
-#define MULTI_SIO_UNK_x2000         0x2000
+#define MULTI_SIO_RECV_ID_SHIFT         0
+#define MULTI_SIO_CONNECTED_ID_SHIFT    8
+
+#define MULTI_SIO_RECV_ID0              0x0001  // Receive success flag Master
+#define MULTI_SIO_RECV_ID1              0x0002  // Slave 1
+#define MULTI_SIO_RECV_ID2              0x0004  // Slave 2
+#define MULTI_SIO_RECV_ID3              0x0008  // Slave 3
+#define MULTI_SIO_LD_ENABLE             0x0010  // Enable load
+#define MULTI_SIO_LD_REQUEST            0x0020  // Load request
+#define MULTI_SIO_LD_SUCCESS            0x0040  // Load success
+#define MULTI_SIO_TYPE                  0x0080  // Connection (Master/Slave)
+#define MULTI_SIO_PARENT                0x0080  // Connect Master
+#define MULTI_SIO_CHILD                 0x0000  // Connect Slave
+#define MULTI_SIO_CONNECTED_ID0         0x0100  // Connection history flag Master
+#define MULTI_SIO_CONNECTED_ID1         0x0200  // Slave 1
+#define MULTI_SIO_CONNECTED_ID2         0x0400  // Slave 2
+#define MULTI_SIO_CONNECTED_ID3         0x0800  // Slave 3
+#define MULTI_SIO_HARD_ERROR            0x1000  // Hard error
+#define MULTI_SIO_ID_OVER_ERROR         0x2000  // ID over error
+#define MULTI_SIO_RECV_FLAGS_AVAILABLE  0x8000  // Validate receive success flag
 
 
 // Return Value Structure
 struct MultiSioReturn
 {
-    u32 recvSuccessFlags:4;                 // Receive Success Flag
-    u32 loadEnable:1;                       // Enable Load
-    u32 loadRequest:1;                      // Load Request
-    u32 loadSuccessFlag:1;                  // Load Success
-    u32 type:1;                             // Connection (Master/Slave)
-    u32 connectedFlags:4;                   // Connection History Flag
-    u32 multisioreturn_unk00_0c:1;
-    u32 multisioreturn_unk00_0d:1;
+    u32 recvSuccessFlags:4;                 // Receive success flag
+    u32 loadEnable:1;                       // Enable load
+    u32 loadRequest:1;                      // Load request
+    u32 loadSuccessFlag:1;                  // Load success
+    u32 type:1;                             // Connection (master/slave) 
+    u32 connectedFlags:4;                   // Connection history flag
+    u32 hardError:1;                        // Hard error
+    u32 idOverError:1;                      // ID over error
+    u32 reserved:1;                         // Reservation
+    u32 recvFlagsAvailable:1;               // Validate receive success flag
 };
 
 
diff --git a/linker.ld b/linker.ld
index 1320f9b..33c0cee 100644
--- a/linker.ld
+++ b/linker.ld
@@ -183,7 +183,7 @@ SECTIONS {
         . = 0x00002548; gUnk_03002548 = .;
         . = 0x0000254C; gUnk_0300254C = .;
         . = 0x00002550; gUnk_03002550 = .;
-        . = 0x00002554; gUnk_03002554 = .;
+        . = 0x00002554; gMultiSioStatusFlags = .;
         . = 0x00002558; gUnk_03002558 = .;
         . = 0x00002560; gTaskList = .;
         . = 0x00002760; gUnk_03002760 = .;
diff --git a/src/main.c b/src/main.c
index ddd1608..15009f9 100644
--- a/src/main.c
+++ b/src/main.c
@@ -196,7 +196,7 @@ void GameInit(void) {
     DmaWait(3);
     DmaFill32(3, 0, gMultiSioRecv, sizeof(gMultiSioRecv));
     DmaWait(3);
-    gUnk_03002554 = 0;
+    gMultiSioStatusFlags = 0;
     gUnk_03002558 = 0;
     MultiSioInit(0);
     gUnk_0300607C = 0;
@@ -205,7 +205,6 @@ void GameInit(void) {
 }
 
 void GameLoop(void) {
-    u32 ret;
     while (1) {
         gUnk_030068D4 = 0;
         gUnk_03002440 &= ~0x01000000;
@@ -219,8 +218,7 @@ void GameLoop(void) {
             GetInput();
             if (gUnk_03002558 != 0) {
                 sub_08030E44();
-                ret = MultiSioMain(&gMultiSioSend, gMultiSioRecv, 0);
-                gUnk_03002554 = ret;
+                gMultiSioStatusFlags = MultiSioMain(&gMultiSioSend, gMultiSioRecv, 0);
                 if (sub_08030FE0() == 0) {
                     sub_08032E98();
                 }
diff --git a/src/multi_08019F28.c b/src/multi_08019F28.c
index 78ca4eb..b27e971 100644
--- a/src/multi_08019F28.c
+++ b/src/multi_08019F28.c
@@ -629,7 +629,7 @@ static void sub_0801A618(struct Multi_08019F28 *r5)
 {
     u32 r3;
 
-    if (gUnk_03002554 & 0x20)
+    if (gMultiSioStatusFlags & MULTI_SIO_LD_REQUEST)
     {
         switch (r5->unk80)
         {
@@ -648,10 +648,10 @@ static void sub_0801A618(struct Multi_08019F28 *r5)
         else
             r5->callback = sub_0801A8E8;
     }
-    if (gUnk_03002554 & 0x10)
-        r5->unkA8 = 1;
+    if (gMultiSioStatusFlags & MULTI_SIO_LD_ENABLE)
+        r5->loadRequest = 1;
     gMultiSioSend.unk0 = gUnk_08D60A80;
-    gUnk_03002554 = MultiSioMain(&gMultiSioSend, gMultiSioRecv, r5->unkA8);
+    gMultiSioStatusFlags = MultiSioMain(&gMultiSioSend, gMultiSioRecv, r5->loadRequest);
     if (r5->unkA4 == 0)
     {
         MultiSioStart();
@@ -684,7 +684,7 @@ static void sub_0801A6BC(struct Multi_08019F28 *r5)
     REG_IME = 0;
     gIntrTable[0] = Sio32MultiLoadIntr;
     REG_IME = 1;
-    Sio32MultiLoadInit(gUnk_03002554 & 0x80, datap);
+    Sio32MultiLoadInit(gMultiSioStatusFlags & MULTI_SIO_TYPE, datap);
     r5->callback = sub_0801A8C4;
 }
 
@@ -792,10 +792,10 @@ static void sub_0801A908(struct Multi_08019F28 *r4)
     REG_IME = 0;
     gIntrTable[0] = (void *)gMultiSioIntrFuncBuf;
     REG_IME = 1;
-    MultiSioInit((gUnk_03002554 & 0xF00) >> 8);
-    r4->unkA8 = 0;
+    MultiSioInit((gMultiSioStatusFlags & MULTI_SIO_CONNECTED_ID_MASK) >> 8);
+    r4->loadRequest = 0;
     r4->unkA4 = 0;
-    gUnk_03002554 = 0;
+    gMultiSioStatusFlags = 0;
 }
 
 static void sub_0801A950(struct Multi_08019F28 *r4)
@@ -861,9 +861,9 @@ static void sub_0801AA40(struct Multi_08019F28 *r4)
 
 static void sub_0801AA58(struct Multi_08019F28 *r2)
 {
-    if (gUnk_03002554 & 0x10)
+    if (gMultiSioStatusFlags & MULTI_SIO_LD_ENABLE)
     {
-        if (gUnk_03002554 & 0x40)
+        if (gMultiSioStatusFlags & MULTI_SIO_LD_SUCCESS)
             ++gMultiSioSend.unk2;
         r2->callback = sub_0801A618;
     }