diff --git a/constants/gfx_constants.asm b/constants/gfx_constants.asm
index 16f3b9855..ff470ff40 100644
--- a/constants/gfx_constants.asm
+++ b/constants/gfx_constants.asm
@@ -39,6 +39,7 @@ DEF REDRAW_ROW EQU 2
 	const BIT_PARTY_MENU_HP_BAR   ; 0
 	const BIT_DOUBLE_SPACED_MENU  ; 1
 	const BIT_SINGLE_SPACED_LINES ; 2
+	const BIT_PAGE_CHAR_IS_NEXT   ; 3
 
 ; tile list ids
 ; TileIDListPointerTable indexes (see data/tilemaps.asm)
diff --git a/engine/battle/core.asm b/engine/battle/core.asm
index 926910fcc..919de01cf 100644
--- a/engine/battle/core.asm
+++ b/engine/battle/core.asm
@@ -2820,7 +2820,10 @@ SelectMenuItem_CursorDown:
 	jp SelectMenuItem
 
 Func_3d4f5:
-	bit 3, a
+IF DEF(_DEBUG)
+	ASSERT BIT_START == BIT_TRAINER_BATTLE
+ENDC
+	bit BIT_TRAINER_BATTLE, a
 	ld a, $0
 	jr nz, .asm_3d4fd
 	ld a, $1
diff --git a/engine/debug/debug_menu.asm b/engine/debug/debug_menu.asm
index ae4a328b2..b2efb940c 100644
--- a/engine/debug/debug_menu.asm
+++ b/engine/debug/debug_menu.asm
@@ -1558,7 +1558,7 @@ Func_ff295:
 	call Func_ff2f3
 	pop de
 	ld a, d
-	set 7, a
+	set BIT_HAS_CHANGED_BOXES, a
 	ld [wCurrentBoxNum], a
 	push de
 	call Func_ff2d1
@@ -1566,7 +1566,7 @@ Func_ff295:
 	call Func_ff2f3
 	ld a, [wLetterPrintingDelayFlags]
 	push af
-	ld a, 1
+	ld a, 1 << BIT_FAST_TEXT_DELAY
 	ld [wLetterPrintingDelayFlags], a
 	callfar SaveSAVtoSRAM
 	pop af
diff --git a/engine/gfx/animated_objects.asm b/engine/gfx/animated_objects.asm
index 208a2f859..0a71f59d5 100644
--- a/engine/gfx/animated_objects.asm
+++ b/engine/gfx/animated_objects.asm
@@ -227,7 +227,7 @@ GetCurrentAnimatedObjectTileYCoordinate:
 	push hl
 	ld a, [hl]
 	ld hl, wCurAnimatedObjectOAMAttributes
-	bit 6, [hl]
+	bit OAM_Y_FLIP, [hl]
 	jr z, .no_flip
 	add $8
 	xor $ff
@@ -240,7 +240,7 @@ GetCurrentAnimatedObjectTileXCoordinate:
 	push hl
 	ld a, [hl]
 	ld hl, wCurAnimatedObjectOAMAttributes
-	bit 5, [hl]
+	bit OAM_X_FLIP, [hl]
 	jr z, .no_flip
 	add $8
 	xor $ff
@@ -254,14 +254,14 @@ SetCurrentAnimatedObjectOAMAttributes:
 	ld b, a
 	ld a, [hl]
 	xor b
-	and $e0
+	and OAM_HFLIP | OAM_VFLIP | OAM_BEHIND_BG
 	ld b, a
 	ld a, [hl]
-	and $10
+	and OAM_OBP1
 	or b
-	bit 4, a
+	bit OAM_OBP_NUM, a
 	ret z
-	or $4
+	or OAM_HIGH_PALS
 	ret
 
 GetCurrentAnimatedObjectOAMDataPointer:
diff --git a/engine/menus/pokedex.asm b/engine/menus/pokedex.asm
index f4637cd06..88a057dfd 100644
--- a/engine/menus/pokedex.asm
+++ b/engine/menus/pokedex.asm
@@ -683,11 +683,11 @@ Pokedex_PrepareDexEntryForPrinting:
 	ld h, a
 	bccoord 1, 1
 	ldh a, [hUILayoutFlags]
-	set 3, a
+	set BIT_PAGE_CHAR_IS_NEXT, a
 	ldh [hUILayoutFlags], a
 	call Pokedex_PrintFlavorTextAtBC
 	ldh a, [hUILayoutFlags]
-	res 3, a
+	res BIT_PAGE_CHAR_IS_NEXT, a
 	ldh [hUILayoutFlags], a
 	ret
 
diff --git a/home/overworld.asm b/home/overworld.asm
index f9aaa089b..2b32eb165 100644
--- a/home/overworld.asm
+++ b/home/overworld.asm
@@ -1233,7 +1233,7 @@ CollisionCheckOnLand::
 	ldh [hTextID], a
 	call IsSpriteInFrontOfPlayer ; check for sprite collisions again? when does the above check fail to detect a sprite collision?
 	jr nc, .asm_0a5c
-	res 7, [hl]
+	res BIT_FACE_PLAYER, [hl]
 	ldh a, [hTextID]
 	and a ; was there a sprite collision?
 	jr z, .asm_0a5c
diff --git a/home/text.asm b/home/text.asm
index d6baf35c8..9bc7f3cff 100644
--- a/home/text.asm
+++ b/home/text.asm
@@ -244,7 +244,7 @@ Paragraph::
 
 PageChar::
 	ldh a, [hUILayoutFlags]
-	bit 3, a
+	bit BIT_PAGE_CHAR_IS_NEXT, a
 	jr z, .pageChar
 	ld a, "<NEXT>"
 	jp PlaceNextChar.NotTerminator
diff --git a/scripts/VermilionCity_2.asm b/scripts/VermilionCity_2.asm
index 8b0126599..c6cd94785 100644
--- a/scripts/VermilionCity_2.asm
+++ b/scripts/VermilionCity_2.asm
@@ -2,7 +2,7 @@ VermilionCityPrintOfficerJennyText::
 	CheckEvent EVENT_GOT_SQUIRTLE_FROM_OFFICER_JENNY
 	jr nz, .asm_f1a69
 	ld a, [wBeatGymFlags]
-	bit 2, a ; THUNDERBADGE
+	bit BIT_THUNDERBADGE, a
 	jr nz, .asm_f1a24
 	ld hl, OfficerJennyText1
 	call PrintText