diff --git a/include/constants/pokemon.h b/include/constants/pokemon.h
index f63d755ad..03b1a7ba1 100644
--- a/include/constants/pokemon.h
+++ b/include/constants/pokemon.h
@@ -21,7 +21,8 @@
 #define TYPE_ICE      0x0f
 #define TYPE_DRAGON   0x10
 #define TYPE_DARK     0x11
-#define NUMBER_OF_MON_TYPES     0x12
+#define TYPE_FAIRY    0x12
+#define NUMBER_OF_MON_TYPES 0x13
 
 
 // Pokemon egg groups
diff --git a/src/data/items.h b/src/data/items.h
index 3bd128811..08e10c5ca 100644
--- a/src/data/items.h
+++ b/src/data/items.h
@@ -2342,7 +2342,7 @@ const struct Item gItems[] =
         .itemId = ITEM_OCCA_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_FIRE,
         .description = sOccaBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2356,7 +2356,7 @@ const struct Item gItems[] =
         .itemId = ITEM_PASSHO_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_WATER,
         .description = sPasshoBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2370,7 +2370,7 @@ const struct Item gItems[] =
         .itemId = ITEM_WACAN_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_ELECTRIC,
         .description = sWacanBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2384,7 +2384,7 @@ const struct Item gItems[] =
         .itemId = ITEM_RINDO_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_GRASS,
         .description = sRindoBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2398,7 +2398,7 @@ const struct Item gItems[] =
         .itemId = ITEM_YACHE_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_ICE,
         .description = sYacheBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2412,7 +2412,7 @@ const struct Item gItems[] =
         .itemId = ITEM_CHOPLE_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_FIGHTING,
         .description = sChopleBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2426,7 +2426,7 @@ const struct Item gItems[] =
         .itemId = ITEM_KEBIA_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_POISON,
         .description = sKebiaBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2440,7 +2440,7 @@ const struct Item gItems[] =
         .itemId = ITEM_SHUCA_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_GROUND,
         .description = sShucaBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2454,7 +2454,7 @@ const struct Item gItems[] =
         .itemId = ITEM_COBA_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_FIGHTING,
         .description = sCobaBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2468,7 +2468,7 @@ const struct Item gItems[] =
         .itemId = ITEM_PAYAPA_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_PSYCHIC,
         .description = sPayapaBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2482,7 +2482,7 @@ const struct Item gItems[] =
         .itemId = ITEM_TANGA_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_BUG,
         .description = sTangaBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2496,7 +2496,7 @@ const struct Item gItems[] =
         .itemId = ITEM_CHARTI_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_ROCK,
         .description = sChartiBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2510,7 +2510,7 @@ const struct Item gItems[] =
         .itemId = ITEM_KASIB_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_GHOST,
         .description = sKasibBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2524,7 +2524,7 @@ const struct Item gItems[] =
         .itemId = ITEM_HABAN_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_DRAGON,
         .description = sHabanBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2538,7 +2538,7 @@ const struct Item gItems[] =
         .itemId = ITEM_COLBUR_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_DARK,
         .description = sColburBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2552,7 +2552,7 @@ const struct Item gItems[] =
         .itemId = ITEM_BABIRI_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_STEEL,
         .description = sBabiriBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2566,7 +2566,7 @@ const struct Item gItems[] =
         .itemId = ITEM_CHILAN_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_NORMAL,
         .description = sChilanBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -2580,7 +2580,7 @@ const struct Item gItems[] =
         .itemId = ITEM_ROSELI_BERRY,
         .price = 20,
         .holdEffect = HOLD_EFFECT_RESIST_BERRY,
-        .holdEffectParam = 0,
+        .holdEffectParam = TYPE_FAIRY,
         .description = sRoseliBerryDesc,
         .pocket = POCKET_BERRIES,
         .type = 4,
@@ -3289,6 +3289,7 @@ const struct Item gItems[] =
         .itemId = ITEM_POWER_BRACER,
         .price = 3000,
         .holdEffect = HOLD_EFFECT_EV_BOOST,
+        .holdEffectParam = 4,
         .description = sPowerBracerDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3302,6 +3303,7 @@ const struct Item gItems[] =
         .itemId = ITEM_POWER_BELT,
         .price = 3000,
         .holdEffect = HOLD_EFFECT_EV_BOOST,
+        .holdEffectParam = 4,
         .description = sPowerBeltDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3315,6 +3317,7 @@ const struct Item gItems[] =
         .itemId = ITEM_POWER_LENS,
         .price = 3000,
         .holdEffect = HOLD_EFFECT_EV_BOOST,
+        .holdEffectParam = 4,
         .description = sPowerLensDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3328,6 +3331,7 @@ const struct Item gItems[] =
         .itemId = ITEM_POWER_BAND,
         .price = 3000,
         .holdEffect = HOLD_EFFECT_EV_BOOST,
+        .holdEffectParam = 4,
         .description = sPowerBandDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3341,6 +3345,7 @@ const struct Item gItems[] =
         .itemId = ITEM_POWER_ANKLET,
         .price = 3000,
         .holdEffect = HOLD_EFFECT_EV_BOOST,
+        .holdEffectParam = 4,
         .description = sPowerAnkletDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3354,6 +3359,7 @@ const struct Item gItems[] =
         .itemId = ITEM_POWER_WEIGHT,
         .price = 3000,
         .holdEffect = HOLD_EFFECT_EV_BOOST,
+        .holdEffectParam = 4,
         .description = sPowerWeightDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -6217,7 +6223,7 @@ const struct Item gItems[] =
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_WATER,
     },
 
     [ITEM_SHOCK_DRIVE] =
@@ -6230,7 +6236,7 @@ const struct Item gItems[] =
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_ELECTRIC,
     },
 
     [ITEM_BURN_DRIVE] =
@@ -6243,7 +6249,7 @@ const struct Item gItems[] =
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_FIRE,
     },
 
     [ITEM_CHILL_DRIVE] =
@@ -6256,7 +6262,7 @@ const struct Item gItems[] =
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_ICE,
     },
 
     [ITEM_FIRE_GEM] =
@@ -6265,11 +6271,12 @@ const struct Item gItems[] =
         .itemId = ITEM_FIRE_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sFireGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_FIRE,
     },
 
     [ITEM_WATER_GEM] =
@@ -6278,11 +6285,12 @@ const struct Item gItems[] =
         .itemId = ITEM_WATER_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sWaterGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_WATER,
     },
 
     [ITEM_ELECTRIC_GEM] =
@@ -6291,11 +6299,12 @@ const struct Item gItems[] =
         .itemId = ITEM_ELECTRIC_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sElectricGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_ELECTRIC,
     },
 
     [ITEM_GRASS_GEM] =
@@ -6304,11 +6313,12 @@ const struct Item gItems[] =
         .itemId = ITEM_GRASS_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sGrassGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_GRASS,
     },
 
     [ITEM_ICE_GEM] =
@@ -6317,6 +6327,7 @@ const struct Item gItems[] =
         .itemId = ITEM_ICE_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sIceGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -6330,6 +6341,7 @@ const struct Item gItems[] =
         .itemId = ITEM_FIGHTING_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sFightingGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -6343,11 +6355,12 @@ const struct Item gItems[] =
         .itemId = ITEM_POISON_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sPoisonGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_POISON,
     },
 
     [ITEM_GROUND_GEM] =
@@ -6356,11 +6369,12 @@ const struct Item gItems[] =
         .itemId = ITEM_GROUND_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sGroundGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_GROUND,
     },
 
     [ITEM_FLYING_GEM] =
@@ -6369,11 +6383,12 @@ const struct Item gItems[] =
         .itemId = ITEM_FLYING_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sFlyingGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_FLYING,
     },
 
     [ITEM_PSYCHIC_GEM] =
@@ -6382,11 +6397,12 @@ const struct Item gItems[] =
         .itemId = ITEM_PSYCHIC_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sPsychicGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_PSYCHIC,
     },
 
     [ITEM_BUG_GEM] =
@@ -6395,11 +6411,12 @@ const struct Item gItems[] =
         .itemId = ITEM_BUG_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sBugGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_BUG,
     },
 
     [ITEM_ROCK_GEM] =
@@ -6408,11 +6425,12 @@ const struct Item gItems[] =
         .itemId = ITEM_ROCK_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sRockGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_ROCK,
     },
 
     [ITEM_GHOST_GEM] =
@@ -6421,11 +6439,12 @@ const struct Item gItems[] =
         .itemId = ITEM_GHOST_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sGhostGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_GHOST,
     },
 
     [ITEM_DRAGON_GEM] =
@@ -6434,11 +6453,12 @@ const struct Item gItems[] =
         .itemId = ITEM_DRAGON_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sDragonGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_DRAGON,
     },
 
     [ITEM_DARK_GEM] =
@@ -6447,11 +6467,12 @@ const struct Item gItems[] =
         .itemId = ITEM_DARK_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sDarkGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_DARK,
     },
 
     [ITEM_STEEL_GEM] =
@@ -6460,11 +6481,12 @@ const struct Item gItems[] =
         .itemId = ITEM_STEEL_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sSteelGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_STEEL,
     },
 
     [ITEM_NORMAL_GEM] =
@@ -6473,11 +6495,12 @@ const struct Item gItems[] =
         .itemId = ITEM_NORMAL_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sNormalGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_NORMAL,
     },
 
     [ITEM_FAIRY_GEM] =
@@ -6486,11 +6509,12 @@ const struct Item gItems[] =
         .itemId = ITEM_FAIRY_GEM,
         .price = 200,
         .holdEffect = HOLD_EFFECT_GEMS,
+        .holdEffectParam = 30,
         .description = sFairyGemDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
         .fieldUseFunc = ItemUseOutOfBattle_CannotUse,
-        .secondaryId = 0,
+        .secondaryId = TYPE_FAIRY,
     },
 
     [ITEM_ASSAULT_VEST] =