the stuff

code/modules/clothing/under/accessories.dm

@@ -4,7 +4,8 @@
 	icon = 'icons/obj/clothing/accessories.dmi'
 	icon_state = "plasma"
 	item_state = ""	//no inhands
-	slot_flags = 0
+	slot_flags = ITEM_SLOT_ACCESSORY
+	slot_equipment_priority = list(ITEM_SLOT_ACCESSORY)
 	w_class = WEIGHT_CLASS_SMALL
 	var/above_suit = FALSE
 	var/minimize_when_attached = TRUE // TRUE if shown as a small icon in corner, FALSE if overlayed

code/modules/mob/dead/new_player/preferences_setup.dm

@@ -51,7 +51,8 @@
 
 	if(current_tab == LOADOUT_TAB)
 		//give it its loadout if not on the appearance tab
-		SSjob.equip_loadout(parent.mob, mannequin, FALSE, bypass_prereqs = TRUE, can_drop = FALSE)
+		SSjob.equip_loadout(parent.mob, mannequin, bypass_prereqs = TRUE, can_drop = FALSE)
+		SSjob.post_equip_loadout(parent.mob, mannequin, bypass_prereqs = TRUE, can_drop = FALSE)
 	else
 		if(previewJob && equip_job)
 			mannequin.job = previewJob.title

code/modules/mob/living/carbon/human/inventory.dm

@@ -148,6 +148,10 @@
 		if(ITEM_SLOT_SUITSTORE)
 			s_store = I
 			update_inv_s_store()
+		if(ITEM_SLOT_ACCESSORY)
+			var/obj/item/clothing/under/attach_target = w_uniform
+			attach_target.attach_accessory(I, src, TRUE)
+			// updates handled by attach_accessory
 		else
 			to_chat(src, "<span class='danger'>You are trying to equip this item to an unsupported inventory slot. Report this to a coder!</span>")
 			not_handled = TRUE

code/modules/mob/living/carbon/human/species.dm

@@ -1454,6 +1454,22 @@ GLOBAL_LIST_EMPTY(roundstart_race_names)
 				if(SEND_SIGNAL(H.back, COMSIG_TRY_STORAGE_CAN_INSERT, I, H, TRUE))
 					return TRUE
 			return FALSE
+		if(ITEM_SLOT_ACCESSORY)
+			if(istype(H.w_uniform, /obj/item/clothing/under))
+				var/obj/item/clothing/under/attaching_target = H.w_uniform
+				if(attaching_target.attached_accessory)
+					if(return_warning)
+						return_warning[1] = "\The [attaching_target] already has an accessory."
+					return FALSE
+				if(attaching_target.dummy_thick)
+					if(return_warning)
+						return_warning[1] = "\The [attaching_target] is too bulky and cannot have accessories attached to it!"
+					return FALSE
+				else
+					return TRUE
+			else if(return_warning)
+				return_warning[1] = "\The [H.w_uniform] cannot have any attachments."
+			return FALSE
 	return FALSE //Unsupported slot
 
 /datum/species/proc/equip_delay_self_check(obj/item/I, mob/living/carbon/human/H, bypass_equip_delay_self)