diff --git a/code/__DEFINES/_flags/item_flags.dm b/code/__DEFINES/_flags/item_flags.dm
index c6e60bf07ca..8235fa8c69a 100644
--- a/code/__DEFINES/_flags/item_flags.dm
+++ b/code/__DEFINES/_flags/item_flags.dm
@@ -40,6 +40,7 @@ DEFINE_BITFIELD(item_flags, list(
 	BITFIELD(SURGICAL_TOOL),
 	BITFIELD(IN_STORAGE),
 	BITFIELD(ITEM_THROW_UNCATCHABLE),
+	BITFIELD(ITEM_NO_TOOL_ATTACK),
 ))
 
 //! Flags for the clothing_flags var on /obj/item
diff --git a/code/__DEFINES/inventory/slots.dm b/code/__DEFINES/inventory/slots.dm
index 0366a8c9dbd..d6a73c83146 100644
--- a/code/__DEFINES/inventory/slots.dm
+++ b/code/__DEFINES/inventory/slots.dm
@@ -29,6 +29,11 @@
 /// use proc
 #define SLOT_EQUIP_CHECK_USE_PROC			(1<<1)
 
+DEFINE_BITFIELD(slot_equip_checks, list(
+	BITFIELD(SLOT_EQUIP_CHECK_USE_FLAGS),
+	BITFIELD(SLOT_EQUIP_CHECK_USE_PROC),
+))
+
 //! slot meta inventory_slot_flags flags
 /// render on mob
 #define INV_SLOT_IS_RENDERED				(1<<0)
@@ -49,6 +54,18 @@
 /// do not show on strip panel unless it's occupied by an item
 #define INV_SLOT_STRIP_ONLY_REMOVES			(1<<8)
 
+DEFINE_BITFIELD(inventory_slot_flags, list(
+	BITFIELD(INV_SLOT_IS_RENDERED),
+	BITFIELD(INV_SLOT_CONSIDERED_WORN),
+	BITFIELD(INV_SLOT_ALLOW_RANDOM_ID),
+	BITFIELD(INV_SLOT_IS_INVENTORY),
+	BITFIELD(INV_SLOT_HUD_REQUIRES_EXPAND),
+	BITFIELD(INV_SLOT_IS_ABSTRACT),
+	BITFIELD(INV_SLOT_IS_STRIPPABLE),
+	BITFIELD(INV_SLOT_STRIP_SIMPLE_LINK),
+	BITFIELD(INV_SLOT_STRIP_ONLY_REMOVES),
+))
+
 //! slot flags
 // Item inventory slot bitmasks.
 #define SLOT_OCLOTHING  (1<<0)
@@ -73,6 +90,29 @@
 // todo: this shouldn't be a slot flag wtf
 #define SLOT_HOLSTER	(1<<15)
 
+#define SLOT_FLAG_BITFIELDS list( \
+	BITFIELD(SLOT_OCLOTHING), \
+	BITFIELD(SLOT_ICLOTHING), \
+	BITFIELD(SLOT_GLOVES), \
+	BITFIELD(SLOT_EYES), \
+	BITFIELD(SLOT_EARS), \
+	BITFIELD(SLOT_MASK), \
+	BITFIELD(SLOT_HEAD), \
+	BITFIELD(SLOT_FEET), \
+	BITFIELD(SLOT_ID), \
+	BITFIELD(SLOT_BELT), \
+	BITFIELD(SLOT_BACK), \
+	BITFIELD(SLOT_POCKET), \
+	BITFIELD(SLOT_DENYPOCKET), \
+	BITFIELD(SLOT_TWOEARS), \
+	BITFIELD(SLOT_TIE), \
+	BITFIELD(SLOT_HOLSTER), \
+)
+
+DEFINE_BITFIELD(slot_flags, SLOT_FLAG_BITFIELDS)
+DEFINE_BITFIELD(slot_flags_required, SLOT_FLAG_BITFIELDS)
+DEFINE_BITFIELD(slot_flags_forbidden, SLOT_FLAG_BITFIELDS)
+
 //! legacy
 /// Takes 40ds = 4s to strip someone.
 #define HUMAN_STRIP_DELAY		4 SECONDS
diff --git a/code/game/objects/structures/door_assembly.dm b/code/game/objects/structures/door_assembly.dm
index b9a8c4b4ba5..e4d9c5c59a6 100644
--- a/code/game/objects/structures/door_assembly.dm
+++ b/code/game/objects/structures/door_assembly.dm
@@ -228,7 +228,7 @@
 		playsound(src, W.tool_sound, 100, 1)
 		user.visible_message("[user] cuts the wires from the airlock assembly.", "You start to cut the wires from airlock assembly.")
 
-		if(do_after(user, 40 * W.tool_speed))
+		if(do_after(user, 40 * W.tool_speed) && state == 1)
 			if(!src) return
 			to_chat(user, "<span class='notice'>You cut the airlock wires.!</span>")
 			new/obj/item/stack/cable_coil(src.loc, 1)
diff --git a/code/modules/mob/inventory/items.dm b/code/modules/mob/inventory/items.dm
index 57acc7c3f6c..7a248630cb3 100644
--- a/code/modules/mob/inventory/items.dm
+++ b/code/modules/mob/inventory/items.dm
@@ -198,7 +198,7 @@
  * checks if we need something to attach to in a certain slot
  */
 /obj/item/proc/equip_check_beltlink(mob/M, slot, mob/user, flags)
-	if(item_flags & EQUIP_IGNORE_BELTLINK)
+	if(clothing_flags & EQUIP_IGNORE_BELTLINK)
 		return TRUE
 
 	if(!ishuman(M))
diff --git a/code/modules/mob/living/life.dm b/code/modules/mob/living/life.dm
index 6077f4a4fd6..d3750a813b3 100644
--- a/code/modules/mob/living/life.dm
+++ b/code/modules/mob/living/life.dm
@@ -5,14 +5,15 @@
 	if(machine && !CanMouseDrop(machine, src))
 		machine = null
 
-	handle_regular_hud_updates()
-	handle_vision()
-	handle_light()
-
 	if(handle_regular_UI_updates()) // Status & health update, are we dead or alive etc.
 		handle_disabilities() // eye, ear, brain damages
 		handle_statuses() //all special effects, stunned, weakened, jitteryness, hallucination, sleeping, etc
 
+	handle_regular_hud_updates()
+
+	handle_vision()
+	handle_light()
+
 	handle_actions()
 	update_canmove()
 
diff --git a/code/modules/organs/external/_external_icons.dm b/code/modules/organs/external/_external_icons.dm
index 60d9c999d11..ff134a35f23 100644
--- a/code/modules/organs/external/_external_icons.dm
+++ b/code/modules/organs/external/_external_icons.dm
@@ -1,4 +1,4 @@
-var/global/list/limb_icon_cache = list()
+GLOBAL_LIST_EMPTY(limb_icon_cache)
 
 /obj/item/organ/external/proc/compile_icon()
 	cut_overlays()
@@ -189,11 +189,11 @@ var/global/list/limb_icon_cache = list()
 
 			if(body_hair && islist(h_col) && h_col.len >= 3)
 				var/cache_key = "[body_hair]-[icon_name]-[h_col[1]][h_col[2]][h_col[3]]"
-				if(!limb_icon_cache[cache_key])
+				if(!GLOB.limb_icon_cache[cache_key])
 					var/icon/I = icon(species.get_icobase(owner), "[icon_name]_[body_hair]")
 					I.Blend(rgb(h_col[1],h_col[2],h_col[3]), ICON_MULTIPLY)
-					limb_icon_cache[cache_key] = I
-				mob_icon.Blend(limb_icon_cache[cache_key], ICON_OVERLAY)
+					GLOB.limb_icon_cache[cache_key] = I
+				mob_icon.Blend(GLOB.limb_icon_cache[cache_key], ICON_OVERLAY)
 
 	if(model)
 		icon_cache_key += "_model_[model]"
@@ -209,11 +209,11 @@ var/global/list/limb_icon_cache = list()
 
 		if(body_hair && islist(h_col) && h_col.len >= 3)
 			var/cache_key = "[body_hair]-[icon_name]-[h_col[1]][h_col[2]][h_col[3]]"
-			if(!limb_icon_cache[cache_key])
+			if(!GLOB.limb_icon_cache[cache_key])
 				var/icon/I = icon(species.get_icobase(owner), "[icon_name]_[body_hair]")
 				I.Blend(rgb(h_col[1],h_col[2],h_col[3]), ICON_MULTIPLY)
-				limb_icon_cache[cache_key] = I
-			mob_icon.Blend(limb_icon_cache[cache_key], ICON_OVERLAY)
+				GLOB.limb_icon_cache[cache_key] = I
+			mob_icon.Blend(GLOB.limb_icon_cache[cache_key], ICON_OVERLAY)
 
 	dir = EAST
 	icon = mob_icon
@@ -280,9 +280,9 @@ var/list/robot_hud_colours = list("#CFCFCF","#AFAFAF","#8F8F8F","#6F6F6F","#4F4F
 	// This looks convoluted, but it's this way to avoid icon proc calls.
 	if(!hud_damage_image)
 		var/cache_key = "dambase-[icon_cache_key]"
-		if(!icon_cache_key || !limb_icon_cache[cache_key])
-			limb_icon_cache[cache_key] = icon(get_icon(), null, SOUTH)
-		var/image/temp = image(limb_icon_cache[cache_key])
+		if(!icon_cache_key || !GLOB.limb_icon_cache[cache_key])
+			GLOB.limb_icon_cache[cache_key] = icon(get_icon(), null, SOUTH)
+		var/image/temp = image(GLOB.limb_icon_cache[cache_key])
 		if((robotic < ORGAN_ROBOT) && species)
 			// Calculate the required colour matrix.
 			var/r = 0.30 * species.health_hud_intensity
diff --git a/code/modules/organs/external/species/diona.dm b/code/modules/organs/external/species/diona.dm
index f647ad81eec..67d7aca36c1 100644
--- a/code/modules/organs/external/species/diona.dm
+++ b/code/modules/organs/external/species/diona.dm
@@ -36,7 +36,7 @@
 	vital = TRUE
 	cannot_amputate = TRUE
 	parent_organ = null
-	gendered_icon = TRUE
+	gendered_icon = FALSE
 
 /obj/item/organ/external/diona/groin
 	name = "fork"
@@ -47,7 +47,7 @@
 	w_class = ITEMSIZE_LARGE
 	body_part = LOWER_TORSO
 	parent_organ = BP_TORSO
-	gendered_icon = TRUE
+	gendered_icon = FALSE
 
 /obj/item/organ/external/diona/arm
 	name = "left upper tendril"