diff --git a/include/unk_0205D8CC.h b/include/unk_0205D8CC.h
index 49bf9b589b..5200d66057 100644
--- a/include/unk_0205D8CC.h
+++ b/include/unk_0205D8CC.h
@@ -12,7 +12,7 @@ void FieldMessaage_FillWindowTilemap(Window *window);
 u8 FieldMessage_Print(Window *window, Strbuf *strBuf, const Options *options, u8 canSkipDelay);
 u8 FieldMessage_PrintWithParams(Window *window, Strbuf *strBuf, int fontID, int renderDelay, u8 canSkipDelay, BOOL autoScroll);
 u8 FieldMessage_FinishedPrinting(u8 printerID);
-void sub_0205DA1C(BgConfig *bgConfig, Window *window, u16 param2, u16 param3);
+void FieldMessage_AddSignpostWindow(BgConfig *bgConfig, Window *window, u16 signpostType, u16 param3);
 void FieldMessage_LoadAndDrawSignpost(Window *window, u16 signpostType, u16 signpostNARCMemberIdx);
 
 #endif // POKEPLATINUM_UNK_0205D8CC_H
diff --git a/src/overlay005/ov5_021E1B08.c b/src/overlay005/ov5_021E1B08.c
index 8a6ff1823b..a9c7817f13 100644
--- a/src/overlay005/ov5_021E1B08.c
+++ b/src/overlay005/ov5_021E1B08.c
@@ -109,7 +109,7 @@ static void ov5_021E1BE0(FieldSystem *fieldSystem)
     Bg_SetOffset(fieldSystem->bgConfig, 3, 3, -48);
 
     if (fieldSystem->unk_64->unk_13_7 == 0) {
-        sub_0205DA1C(fieldSystem->bgConfig, &fieldSystem->unk_64->unk_00, fieldSystem->unk_64->unk_12, 3);
+        FieldMessage_AddSignpostWindow(fieldSystem->bgConfig, &fieldSystem->unk_64->unk_00, fieldSystem->unk_64->unk_12, 3);
         fieldSystem->unk_64->unk_13_7 = 1;
     }
 
diff --git a/src/unk_0205D8CC.c b/src/unk_0205D8CC.c
index 8d8a1e41e5..f7ecd7edaf 100644
--- a/src/unk_0205D8CC.c
+++ b/src/unk_0205D8CC.c
@@ -71,11 +71,11 @@ u8 FieldMessage_FinishedPrinting(u8 printerID)
 }
 
 // used only in one instance
-void sub_0205DA1C(BgConfig *bgConfig, Window *window, u16 param2, u16 param3)
+void FieldMessage_AddSignpostWindow(BgConfig *bgConfig, Window *window, u16 signpostType, u16 param3)
 {
     u16 tilemapLeft, width;
 
-    if ((param2 == 0) || (param2 == 1)) {
+    if (signpostType == SIGNPOST_CITY_MAP || signpostType == SIGNPOST_ROUTE_MAP) {
         tilemapLeft = 9;
         width = 20;
     } else {
@@ -90,7 +90,7 @@ void sub_0205DA1C(BgConfig *bgConfig, Window *window, u16 param2, u16 param3)
     }
 }
 
-// used only in one instance
+// used only in one instance, together with FieldMessage_AddSignpostWindow
 void FieldMessage_LoadAndDrawSignpost(Window *window, u16 signpostType, u16 signpostNARCMemberIdx)
 {
     LoadSignpostContentGraphics(window->bgConfig, Window_GetBgLayer(window), ((1024 - (18 + 12) - 9 - (32 * 8)) - (18 + 12 + 24)), 9, signpostType, signpostNARCMemberIdx, HEAP_ID_FIELD);