diff --git a/include/dungeon_generation_fixed.h b/include/dungeon_generation_fixed.h
index 12a3a3b93..fefa4cee7 100644
--- a/include/dungeon_generation_fixed.h
+++ b/include/dungeon_generation_fixed.h
@@ -4,7 +4,7 @@
 #include "structs/dungeon_entity.h"
 #include "structs/map.h"
 
-bool8 PlaceFixedRoomTile(Tile *tile, u8 a1, s32 x, s32 y, u8 a5);
+bool8 PlaceFixedRoomTile(Tile *tile, u8 fixedRoomActionId, s32 x, s32 y, bool8 spawnTrapOrItem);
 void sub_8051E3C(void);
 void sub_8051E7C(Entity *pokemon);
 
diff --git a/src/dungeon_generation.c b/src/dungeon_generation.c
index c77234019..c31355867 100644
--- a/src/dungeon_generation.c
+++ b/src/dungeon_generation.c
@@ -5887,11 +5887,11 @@ static u8 sub_80511F0(void)
     return gUnknown_202F1E0;
 }
 
-static bool8 sub_805124C(Tile *tile, u8 a1, s32 x, s32 y, u8 a5)
+static bool8 sub_805124C(Tile *tile, u8 a1, s32 x, s32 y, bool8 spawnTrapOrItem)
 {
     tile->terrainType |= TERRAIN_TYPE_UNBREAKABLE;
     tile->unkE = 0;
-    return PlaceFixedRoomTile(tile, a1, x, y, a5);
+    return PlaceFixedRoomTile(tile, a1, x, y, spawnTrapOrItem);
 }
 
 static void sub_8051288(s32 fixedRoomNumber)
@@ -5909,7 +5909,7 @@ static void sub_8051288(s32 fixedRoomNumber)
     for (y = 5; y < fixedRoomSizeY + 5; y++) {
         for (x = 5; x < fixedRoomSizeX + 5; x++) {
             u8 unk = sub_80511F0();
-            if (sub_805124C(GetTileMut(x, y), unk, x, y, 1)) {
+            if (sub_805124C(GetTileMut(x, y), unk, x, y, TRUE)) {
                 dungeon->stairsSpawn.x = x;
                 dungeon->stairsSpawn.y = y;
             }
@@ -5980,7 +5980,7 @@ static void sub_8051438(struct GridCell *gridCell, s32 fixedRoomNumber)
                 Tile *tile = GetTileMut(x, y);
 
                 dungeon->unkE87C[xIndex][yIndex] = unk;
-                sub_805124C(&dungeon->unkE27C[xIndex][yIndex], unk, x, y, 0);
+                sub_805124C(&dungeon->unkE27C[xIndex][yIndex], unk, x, y, FALSE);
                 roomId = tile->room;
                 *tile = dungeon->unkE27C[xIndex][yIndex];
                 if (x >= gridCell->start.x + 2 && x < gridCell->end.x - 2 && y >= gridCell->start.y + 2 && y < gridCell->end.y - 2) {
@@ -6001,7 +6001,7 @@ static void sub_8051438(struct GridCell *gridCell, s32 fixedRoomNumber)
                 Tile *tile = GetTileMut(x, y);
                 u8 roomId = tile->room;
 
-                sub_805124C(tile, unk, x, y, 1);
+                sub_805124C(tile, unk, x, y, TRUE);
                 tile->room = roomId;
                 dungeon->unkE8BC = roomId;
             }
diff --git a/src/dungeon_generation_fixed.c b/src/dungeon_generation_fixed.c
index cc12b79dd..58fa57278 100644
--- a/src/dungeon_generation_fixed.c
+++ b/src/dungeon_generation_fixed.c
@@ -11,13 +11,16 @@
 #include "dungeon_message.h"
 #include "code_803E668.h"
 #include "structs/str_806B7F8.h"
+#include "constants/monster.h"
+#include "constants/trap.h"
+#include "constants/item.h"
 
 extern s32 sub_803DA20(s16 species);
 extern void sub_80429FC(DungeonPos *r0);
 
 static bool8 sub_805210C(u8 itemId);
 
-static void sub_805193C(u8 itemId, s32 x, s32 y, s32 quantity, u32 itemFlags)
+static void SpawnItemAtPos(u8 itemId, s32 x, s32 y, s32 quantity, u32 itemFlags)
 {
     Item item;
     DungeonPos pos = {x, y};
@@ -38,7 +41,7 @@ static void sub_805193C(u8 itemId, s32 x, s32 y, s32 quantity, u32 itemFlags)
 }
 
 // s16 species memes strike again. Will the fix ever be discovered?
-static void sub_8051998(s16 species_, s32 x, s32 y, u32 unk2_, u32 UNUSED unused)
+static void SpawnSpeciesAtPos(s16 species_, s32 x, s32 y, u32 unk2_, u32 UNUSED unused)
 {
     struct unkStruct_806B7F8 unkStruct;
     s32 species = SpeciesId(species_);
@@ -83,21 +86,21 @@ static void SpawnEnemyTrapAtPos(u8 trapId, s32 x, s32 y, bool8 isVisible)
 
 struct UnkStruct_80F6D20
 {
-    u8 unk0;
+    u8 itemId;
     s16 unk2;
     u32 unk4;
-    s16 unk8;
+    s16 speciesId;
     u8 unkA;
-    u8 unkB;
-    u8 unkC;
-    u8 unkD;
-    u8 unkE;
+    u8 trapId;
+    u8 roomId;
+    bool8 trapVisible;
+    bool8 setTerrainToSecondary;
 };
 
 extern const struct UnkStruct_80F6D20 gUnknown_80F6E20[];
 
 // Used to spawn a single tile when generating a fixed room. The tile might contain an item or a monster.
-bool8 PlaceFixedRoomTile(Tile *tile, u8 fixedRoomActionId, s32 x, s32 y, bool8 a5)
+bool8 PlaceFixedRoomTile(Tile *tile, u8 fixedRoomActionId, s32 x, s32 y, bool8 spawnTrapOrItem)
 {
     if (fixedRoomActionId > 0xF) {
         SetTerrainNormal(tile);
@@ -182,13 +185,13 @@ bool8 PlaceFixedRoomTile(Tile *tile, u8 fixedRoomActionId, s32 x, s32 y, bool8 a
         default:
             if (fixedRoomActionId >= 16 && fixedRoomActionId <= 219) {
                 const struct UnkStruct_80F6D20 *ptr = &gUnknown_80F6E20[fixedRoomActionId - 16];
-                tile->room = ptr->unkC;
-                if (ptr->unk0 != 0) {
-                    if (a5) {
-                        sub_805193C(ptr->unk0, x, y, ptr->unk2, ptr->unk4);
+                tile->room = ptr->roomId;
+                if (ptr->itemId != 0) {
+                    if (spawnTrapOrItem) {
+                        SpawnItemAtPos(ptr->itemId, x, y, ptr->unk2, ptr->unk4);
                     }
                     else {
-                        gDungeon->unk644.unk47 = ptr->unk0;
+                        gDungeon->unk644.unk47 = ptr->itemId;
                     }
                 }
                 else {
@@ -198,15 +201,15 @@ bool8 PlaceFixedRoomTile(Tile *tile, u8 fixedRoomActionId, s32 x, s32 y, bool8 a
                     }
                 }
 
-                if (ptr->unk8 != 0) {
-                    sub_8051998(ptr->unk8, x, y, ptr->unkA, fixedRoomActionId);
+                if (ptr->speciesId != 0) {
+                    SpawnSpeciesAtPos(ptr->speciesId, x, y, ptr->unkA, fixedRoomActionId);
                 }
 
-                if (ptr->unkB != 20 && a5) {
-                    SpawnEnemyTrapAtPos(ptr->unkB, x, y, ptr->unkD);
+                if (ptr->trapId != NUM_TRAPS && spawnTrapOrItem) {
+                    SpawnEnemyTrapAtPos(ptr->trapId, x, y, ptr->trapVisible);
                 }
 
-                if (ptr->unkE != 0) {
+                if (ptr->setTerrainToSecondary) {
                     SetTerrainSecondary(tile);
                 }
             }