diff --git a/api.lua b/api.lua
index d24135b..bf2c43c 100644
--- a/api.lua
+++ b/api.lua
@@ -11,8 +11,8 @@ minetest.after(0.01, function()
 	unified_inventory.items_list = {}
 	for name, def in pairs(minetest.registered_items) do
 		if (not def.groups.not_in_creative_inventory or
-		   def.groups.not_in_creative_inventory == 0) and
-		   def.description and def.description ~= "" then
+				def.groups.not_in_creative_inventory == 0) and
+				def.description and def.description ~= "" then
 			table.insert(unified_inventory.items_list, name)
 			local all_names = rev_aliases[name] or {}
 			table.insert(all_names, name)
diff --git a/bags.lua b/bags.lua
index c61c982..d8a29b3 100644
--- a/bags.lua
+++ b/bags.lua
@@ -1,8 +1,8 @@
 --[[
-Bags for Minetest
+	Bags for Minetest
 
-Copyright (c) 2012 cornernote, Brett O'Donnell <cornernote@gmail.com>
-License: GPLv3
+	Copyright (c) 2012 cornernote, Brett O'Donnell <cornernote@gmail.com>
+	License: GPLv3
 --]]
 
 local S = minetest.get_translator("unified_inventory")
@@ -31,7 +31,7 @@ unified_inventory.register_button("bags", {
 	type = "image",
 	image = "ui_bags_icon.png",
 	tooltip = S("Bags"),
-	hide_lite=true
+	hide_lite = true
 })
 
 local function get_player_bag_stack(player, i)
@@ -168,12 +168,12 @@ end
 minetest.register_on_joinplayer(function(player)
 	local player_name = player:get_player_name()
 	local bags_inv = minetest.create_detached_inventory(player_name .. "_bags",{
-		on_put = function(inv, listname, index, stack, player)
+		on_put = function(inv, listname, _, stack, player)
 			player:get_inventory():set_size(listname .. "contents",
 					stack:get_definition().groups.bagslots)
 			save_bags_metadata(player, inv)
 		end,
-		allow_put = function(inv, listname, index, stack, player)
+		allow_put = function(_, listname, _, stack, player)
 			local new_slots = stack:get_definition().groups.bagslots
 			if not new_slots then
 				return 0
@@ -207,13 +207,13 @@ minetest.register_on_joinplayer(function(player)
 			-- New bag is smaller: Disallow inserting
 			return 0
 		end,
-		allow_take = function(inv, listname, index, stack, player)
+		allow_take = function(_, listname, _, stack, player)
 			if player:get_inventory():is_empty(listname .. "contents") then
 				return stack:get_count()
 			end
 			return 0
 		end,
-		on_take = function(inv, listname, index, stack, player)
+		on_take = function(inv, listname, _, _, player)
 			player:get_inventory():set_size(listname .. "contents", 0)
 			save_bags_metadata(player, inv)
 		end,
@@ -229,19 +229,19 @@ end)
 minetest.register_tool("unified_inventory:bag_small", {
 	description = S("Small Bag"),
 	inventory_image = "bags_small.png",
-	groups = {bagslots=8},
+	groups = {bagslots = 8},
 })
 
 minetest.register_tool("unified_inventory:bag_medium", {
 	description = S("Medium Bag"),
 	inventory_image = "bags_medium.png",
-	groups = {bagslots=16},
+	groups = {bagslots = 16},
 })
 
 minetest.register_tool("unified_inventory:bag_large", {
 	description = S("Large Bag"),
 	inventory_image = "bags_large.png",
-	groups = {bagslots=24},
+	groups = {bagslots = 24},
 })
 
 -- register bag crafts
@@ -270,6 +270,6 @@ if minetest.get_modpath("farming") ~= nil then
 			{"",               "",                             ""},
 			{"farming:string", "unified_inventory:bag_medium", "farming:string"},
 			{"farming:string", "unified_inventory:bag_medium", "farming:string"},
-	    },
+		},
 	})
 end
diff --git a/callbacks.lua b/callbacks.lua
index bc90237..f1d32c3 100644
--- a/callbacks.lua
+++ b/callbacks.lua
@@ -27,14 +27,14 @@ minetest.register_on_joinplayer(function(player)
 
 	-- Refill slot
 	local refill = minetest.create_detached_inventory(player_name.."refill", {
-		allow_put = function(inv, listname, index, stack, player)
+		allow_put = function(_, _, _, stack)
 			if unified_inventory.is_creative(player_name) then
 				return stack:get_count()
 			else
 				return 0
 			end
 		end,
-		on_put = function(inv, listname, index, stack, player)
+		on_put = function(inv, listname, index, stack)
 			local handle_refill = (minetest.registered_items[stack:get_name()] or {}).on_refill or default_refill
 			stack = handle_refill(stack)
 			inv:set_stack(listname, index, stack)
@@ -57,7 +57,7 @@ end
 minetest.register_on_player_receive_fields(function(player, formname, fields)
 	local player_name = player:get_player_name()
 
-	local ui_peruser,draw_lite_mode = unified_inventory.get_per_player_formspec(player_name)
+	local ui_peruser, _ = unified_inventory.get_per_player_formspec(player_name)
 
 	if formname ~= "" then
 		return
@@ -69,7 +69,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 		unified_inventory.current_searchbox[player_name] = fields.searchbox
 	end
 
-	for i, def in pairs(unified_inventory.buttons) do
+	for _, def in pairs(unified_inventory.buttons) do
 		if fields[def.name] then
 			def.action(player)
 			minetest.sound_play("click",
@@ -120,7 +120,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 
 	-- Check clicked item image button
 	local clicked_item
-	for name, value in pairs(fields) do
+	for name, _ in pairs(fields) do
 		local new_dir, mangled_item = string.match(name, "^item_button_([a-z]+)_(.*)$")
 		if new_dir and mangled_item then
 			clicked_item = unified_inventory.demangle_for_formspec(mangled_item)
diff --git a/doc/mod_api.txt b/doc/mod_api.txt
index c0be129..45db07a 100644
--- a/doc/mod_api.txt
+++ b/doc/mod_api.txt
@@ -92,4 +92,3 @@ Register a non-standard craft recipe:
 		width = 3,
 		-- ^ Same as `minetest.register_recipe`
 	})
-
diff --git a/group.lua b/group.lua
index 3864267..712dfa8 100644
--- a/group.lua
+++ b/group.lua
@@ -115,7 +115,6 @@ local function compute_group_item(group_name_list)
 	return {item = bestitem, sole = false}
 end
 
-
 local group_item_cache = {}
 
 function unified_inventory.get_group_item(group_name)
@@ -124,4 +123,3 @@ function unified_inventory.get_group_item(group_name)
 	end
 	return group_item_cache[group_name]
 end
-
diff --git a/init.lua b/init.lua
index 1a80abb..9f62bf3 100644
--- a/init.lua
+++ b/init.lua
@@ -50,7 +50,7 @@ unified_inventory = {
 -- Disable default creative inventory
 local creative = rawget(_G, "creative") or rawget(_G, "creative_inventory")
 if creative then
-	function creative.set_creative_formspec(player, start_i, pagenum)
+	function creative.set_creative_formspec()
 		return
 	end
 end
diff --git a/internal.lua b/internal.lua
index ee8b4a9..532a05d 100644
--- a/internal.lua
+++ b/internal.lua
@@ -1,14 +1,16 @@
 local S = minetest.get_translator("unified_inventory")
 local F = minetest.formspec_escape
 
--- This pair of encoding functions is used where variable text must go in
--- button names, where the text might contain formspec metacharacters.
--- We can escape button names for the formspec, to avoid screwing up
--- form structure overall, but they then don't get de-escaped, and so
--- the input we get back from the button contains the formspec escaping.
--- This is a game engine bug, and in the anticipation that it might be
--- fixed some day we don't want to rely on it.  So for safety we apply
--- an encoding that avoids all formspec metacharacters.
+--[[
+	This pair of encoding functions is used where variable text must go in
+	button names, where the text might contain formspec metacharacters.
+	We can escape button names for the formspec, to avoid screwing up
+	form structure overall, but they then don't get de-escaped, and so
+	the input we get back from the button contains the formspec escaping.
+	This is a game engine bug, and in the anticipation that it might be
+	fixed some day we don't want to rely on it.  So for safety we apply
+	an encoding that avoids all formspec metacharacters.
+]]
 function unified_inventory.mangle_for_formspec(str)
 	return string.gsub(str, "([^A-Za-z0-9])", function (c) return string.format("_%d_", string.byte(c)) end)
 end
@@ -47,7 +49,6 @@ function unified_inventory.get_per_player_formspec(player_name)
 end
 
 function unified_inventory.get_formspec(player, page)
-
 	if not player then
 		return ""
 	end
@@ -93,7 +94,7 @@ function unified_inventory.get_formspec(player, page)
 
 	local filtered_inv_buttons = {}
 
-	for i, def in pairs(unified_inventory.buttons) do
+	for _, def in pairs(unified_inventory.buttons) do
 		if not (draw_lite_mode and def.hide_lite) then
 			table.insert(filtered_inv_buttons, def)
 		end
@@ -280,7 +281,7 @@ function unified_inventory.apply_filter(player, filter, search_dir)
 	local ffilter
 	if lfilter:sub(1, 6) == "group:" then
 		local groups = lfilter:sub(7):split(",")
-		ffilter = function(name, def)
+		ffilter = function(_, def)
 			for _, group in ipairs(groups) do
 				if not def.groups[group]
 				or def.groups[group] <= 0 then
diff --git a/item_names.lua b/item_names.lua
index 111c9ee..d769292 100644
--- a/item_names.lua
+++ b/item_names.lua
@@ -73,4 +73,3 @@ minetest.register_globalstep(function(dtime)
 		end
 	end
 end)
-
diff --git a/match_craft.lua b/match_craft.lua
index 2dd40b0..5e0a218 100644
--- a/match_craft.lua
+++ b/match_craft.lua
@@ -3,26 +3,26 @@
 -- according to the recipe.
 
 --[[
-Retrieve items from inventory lists and calculate their total count.
-Return a table of "item name" - "total count" pairs.
+	Retrieve items from inventory lists and calculate their total count.
+	Return a table of "item name" - "total count" pairs.
 
-Arguments:
-	inv: minetest inventory reference
-	lists: names of inventory lists to use
+	Arguments:
+		inv: minetest inventory reference
+		lists: names of inventory lists to use
 
-Example usage:
-	-- Count items in "main" and "craft" lists of player inventory
-	unified_inventory.count_items(player_inv_ref, {"main", "craft"})
+	Example usage:
+		-- Count items in "main" and "craft" lists of player inventory
+		unified_inventory.count_items(player_inv_ref, {"main", "craft"})
 
-Example output:
-	{
-		["default:pine_wood"] = 2,
-		["default:acacia_wood"] = 4,
-		["default:chest"] = 3,
-		["default:axe_diamond"] = 2, -- unstackable item are counted too
-		["wool:white"] = 6
-	}
-]]--
+	Example output:
+		{
+			["default:pine_wood"] = 2,
+			["default:acacia_wood"] = 4,
+			["default:chest"] = 3,
+			["default:axe_diamond"] = 2, -- unstackable item are counted too
+			["wool:white"] = 6
+		}
+]]
 function unified_inventory.count_items(inv, lists)
 	local counts = {}
 
@@ -47,23 +47,23 @@ function unified_inventory.count_items(inv, lists)
 end
 
 --[[
-Retrieve craft recipe items and their positions in the crafting grid.
-Return a table of "craft item name" - "set of positions" pairs.
+	Retrieve craft recipe items and their positions in the crafting grid.
+	Return a table of "craft item name" - "set of positions" pairs.
 
-Note that if craft width is not 3 then positions are recalculated as
-if items were placed on a 3x3 grid. Also note that craft can contain
-groups of items with "group:" prefix.
+	Note that if craft width is not 3 then positions are recalculated as
+	if items were placed on a 3x3 grid. Also note that craft can contain
+	groups of items with "group:" prefix.
 
-Arguments:
-	craft: minetest craft recipe
+	Arguments:
+		craft: minetest craft recipe
 
-Example output:
-	-- Bed recipe
-	{
-		["wool:white"] = {[1] = true, [2] = true, [3] = true}
-		["group:wood"] = {[4] = true, [5] = true, [6] = true}
-	}
---]]
+	Example output:
+		-- Bed recipe
+		{
+			["wool:white"] = {[1] = true, [2] = true, [3] = true}
+			["group:wood"] = {[4] = true, [5] = true, [6] = true}
+		}
+]]
 function unified_inventory.count_craft_positions(craft)
 	local positions = {}
 	local craft_items = craft.items
@@ -99,32 +99,32 @@ function unified_inventory.count_craft_positions(craft)
 end
 
 --[[
-For every craft item find all matching inventory items.
-- If craft item is a group then find all inventory items that matches
-  this group.
-- If craft item is not a group (regular item) then find only this item.
+	For every craft item find all matching inventory items.
+	- If craft item is a group then find all inventory items that matches
+	  this group.
+	- If craft item is not a group (regular item) then find only this item.
 
-If inventory doesn't contain needed item then found set is empty for
-this item.
+	If inventory doesn't contain needed item then found set is empty for
+	this item.
 
-Return a table of "craft item name" - "set of matching inventory items"
-pairs.
+	Return a table of "craft item name" - "set of matching inventory items"
+	pairs.
 
-Arguments:
-	inv_items: table with items names as keys
-	craft_items: table with items names or groups as keys
+	Arguments:
+		inv_items: table with items names as keys
+		craft_items: table with items names or groups as keys
 
-Example output:
-	{
-		["group:wood"] = {
-			["default:pine_wood"] = true,
-			["default:acacia_wood"] = true
-		},
-		["wool:white"] = {
-			["wool:white"] = true
+	Example output:
+		{
+			["group:wood"] = {
+				["default:pine_wood"] = true,
+				["default:acacia_wood"] = true
+			},
+			["wool:white"] = {
+				["wool:white"] = true
+			}
 		}
-	}
---]]
+]]
 function unified_inventory.find_usable_items(inv_items, craft_items)
 	local get_group = minetest.get_item_group
 	local result = {}
@@ -152,28 +152,28 @@ function unified_inventory.find_usable_items(inv_items, craft_items)
 end
 
 --[[
-Match inventory items with craft grid positions.
-For every position select the matching inventory item with maximum
-(total_count / (times_matched + 1)) value.
+	Match inventory items with craft grid positions.
+	For every position select the matching inventory item with maximum
+	(total_count / (times_matched + 1)) value.
 
-If for some position matching item cannot be found or match count is 0
-then return nil.
+	If for some position matching item cannot be found or match count is 0
+	then return nil.
 
-Return a table of "matched item name" - "set of craft positions" pairs
-and overall match count.
+	Return a table of "matched item name" - "set of craft positions" pairs
+	and overall match count.
 
-Arguments:
-	inv_counts: table of inventory items counts from "count_items"
-	craft_positions: table of craft positions from "count_craft_positions"
+	Arguments:
+		inv_counts: table of inventory items counts from "count_items"
+		craft_positions: table of craft positions from "count_craft_positions"
 
-Example output:
-	match_table = {
-		["wool:white"] = {[1] = true, [2] = true, [3] = true}
-		["default:acacia_wood"] = {[4] = true, [6] = true}
-		["default:pine_wood"] = {[5] = true}
-	}
-	match_count = 2
---]]
+	Example output:
+		match_table = {
+			["wool:white"] = {[1] = true, [2] = true, [3] = true}
+			["default:acacia_wood"] = {[4] = true, [6] = true}
+			["default:pine_wood"] = {[5] = true}
+		}
+		match_count = 2
+]]
 function unified_inventory.match_items(inv_counts, craft_positions)
 	local usable = unified_inventory.find_usable_items(inv_counts, craft_positions)
 	local match_table = {}
@@ -227,17 +227,17 @@ function unified_inventory.match_items(inv_counts, craft_positions)
 end
 
 --[[
-Remove item from inventory lists.
-Return stack of actually removed items.
+	Remove item from inventory lists.
+	Return stack of actually removed items.
 
-This function replicates the inv:remove_item function but can accept
-multiple lists.
+	This function replicates the inv:remove_item function but can accept
+	multiple lists.
 
-Arguments:
-	inv: minetest inventory reference
-	lists: names of inventory lists
-	stack: minetest item stack
---]]
+	Arguments:
+		inv: minetest inventory reference
+		lists: names of inventory lists
+		stack: minetest item stack
+]]
 function unified_inventory.remove_item(inv, lists, stack)
 	local removed = ItemStack(nil)
 	local leftover = ItemStack(stack)
@@ -256,17 +256,17 @@ function unified_inventory.remove_item(inv, lists, stack)
 end
 
 --[[
-Add item to inventory lists.
-Return leftover stack.
+	Add item to inventory lists.
+	Return leftover stack.
 
-This function replicates the inv:add_item function but can accept
-multiple lists.
+	This function replicates the inv:add_item function but can accept
+	multiple lists.
 
-Arguments:
-	inv: minetest inventory reference
-	lists: names of inventory lists
-	stack: minetest item stack
---]]
+	Arguments:
+		inv: minetest inventory reference
+		lists: names of inventory lists
+		stack: minetest item stack
+]]
 function unified_inventory.add_item(inv, lists, stack)
 	local leftover = ItemStack(stack)
 
@@ -282,15 +282,15 @@ function unified_inventory.add_item(inv, lists, stack)
 end
 
 --[[
-Move items from source list to destination list if possible.
-Skip positions specified in exclude set.
+	Move items from source list to destination list if possible.
+	Skip positions specified in exclude set.
 
-Arguments:
-	inv: minetest inventory reference
-	src_list: name of source list
-	dst_list: name of destination list
-	exclude: set of positions to skip
---]]
+	Arguments:
+		inv: minetest inventory reference
+		src_list: name of source list
+		dst_list: name of destination list
+		exclude: set of positions to skip
+]]
 function unified_inventory.swap_items(inv, src_list, dst_list, exclude)
 	local size = inv:get_size(src_list)
 	local empty = ItemStack(nil)
@@ -312,21 +312,21 @@ function unified_inventory.swap_items(inv, src_list, dst_list, exclude)
 end
 
 --[[
-Move matched items to the destination list.
+	Move matched items to the destination list.
 
-If destination list position is already occupied with some other item
-then function tries to (in that order):
-1. Move it to the source list
-2. Move it to some other unused position in destination list itself
-3. Drop it to the ground if nothing else is possible.
+	If destination list position is already occupied with some other item
+	then function tries to (in that order):
+	1. Move it to the source list
+	2. Move it to some other unused position in destination list itself
+	3. Drop it to the ground if nothing else is possible.
 
-Arguments:
-	player: minetest player object
-	src_list: name of source list
-	dst_list: name of destination list
-	match_table: table of matched items
-	amount: amount of items per every position
---]]
+	Arguments:
+		player: minetest player object
+		src_list: name of source list
+		dst_list: name of destination list
+		match_table: table of matched items
+		amount: amount of items per every position
+]]
 function unified_inventory.move_match(player, src_list, dst_list, match_table, amount)
 	local inv = player:get_inventory()
 	local item_drop = minetest.item_drop
@@ -374,21 +374,21 @@ function unified_inventory.move_match(player, src_list, dst_list, match_table, a
 end
 
 --[[
-Find craft match and move matched items to the destination list.
+	Find craft match and move matched items to the destination list.
 
-If match cannot be found or match count is smaller than the desired
-amount then do nothing.
+	If match cannot be found or match count is smaller than the desired
+	amount then do nothing.
 
-If amount passed is -1 then amount is defined by match count itself.
-This is used to indicate "craft All" case.
+	If amount passed is -1 then amount is defined by match count itself.
+	This is used to indicate "craft All" case.
 
-Arguments:
-	player: minetest player object
-	src_list: name of source list
-	dst_list: name of destination list
-	craft: minetest craft recipe
-	amount: desired amount of output items
---]]
+	Arguments:
+		player: minetest player object
+		src_list: name of source list
+		dst_list: name of destination list
+		craft: minetest craft recipe
+		amount: desired amount of output items
+]]
 function unified_inventory.craftguide_match_craft(player, src_list, dst_list, craft, amount)
 	local inv = player:get_inventory()
 	local src_dst_list = {src_list, dst_list}
diff --git a/register.lua b/register.lua
index f958a6d..72fe530 100644
--- a/register.lua
+++ b/register.lua
@@ -21,7 +21,7 @@ local trash = minetest.create_detached_inventory("trash", {
 	--		return 0
 	--	end
 	--end,
-	on_put = function(inv, listname, index, stack, player)
+	on_put = function(inv, listname, index, _, player)
 		inv:set_stack(listname, index, nil)
 		local player_name = player:get_player_name()
 		minetest.sound_play("trash", {to_player=player_name, gain = 1.0})
@@ -193,9 +193,9 @@ unified_inventory.register_page("craft", {
 
 -- stack_image_button(): generate a form button displaying a stack of items
 --
--- The specified item may be a group.  In that case, the group will be
+-- The specified item may be a group. In that case, the group will be
 -- represented by some item in the group, along with a flag indicating
--- that it's a group.  If the group contains only one item, it will be
+-- that it's a group. If the group contains only one item, it will be
 -- treated as if that item had been specified directly.
 
 local function stack_image_button(x, y, w, h, buttonname_prefix, item)
@@ -226,7 +226,7 @@ local function stack_image_button(x, y, w, h, buttonname_prefix, item)
 		end
 		grouptip = F(grouptip)
 		if andcount >= 1 then
-			button = button  .. string.format("tooltip[%s;%s]", buttonname, grouptip)
+			button = button .. string.format("tooltip[%s;%s]", buttonname, grouptip)
 		end
 	end
 	return button
@@ -260,8 +260,8 @@ local other_dir = {
 unified_inventory.register_page("craftguide", {
 	get_formspec = function(player, perplayer_formspec)
 
-		local formspecy =    perplayer_formspec.formspec_y
-		local formheadery =  perplayer_formspec.form_header_y
+		local formspecy    = perplayer_formspec.formspec_y
+		local formheadery  = perplayer_formspec.form_header_y
 		local craftresultx = perplayer_formspec.craft_result_x
 		local craftresulty = perplayer_formspec.craft_result_y
 
@@ -414,7 +414,7 @@ unified_inventory.register_page("craftguide", {
 	end,
 })
 
-local function craftguide_giveme(player, formname, fields)
+local function craftguide_giveme(player, _, fields)
 	local player_name = player:get_player_name()
 	local player_privs = minetest.get_player_privs(player_name)
 	if not player_privs.give and
@@ -425,7 +425,7 @@ local function craftguide_giveme(player, formname, fields)
 	end
 
 	local amount
-	for k, v in pairs(fields) do
+	for k, _ in pairs(fields) do
 		amount = k:match("craftguide_giveme_(.*)")
 		if amount then break end
 	end
@@ -441,9 +441,9 @@ local function craftguide_giveme(player, formname, fields)
 	player_inv:add_item("main", {name = output, count = amount})
 end
 
-local function craftguide_craft(player, formname, fields)
+local function craftguide_craft(player, _, fields)
 	local amount
-	for k, v in pairs(fields) do
+	for k, _ in pairs(fields) do
 		amount = k:match("craftguide_craft_(.*)")
 		if amount then break end
 	end
@@ -476,7 +476,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 		return
 	end
 
-	for k, v in pairs(fields) do
+	for k, _ in pairs(fields) do
 		if k:match("craftguide_craft_") then
 			craftguide_craft(player, formname, fields)
 			return
diff --git a/textures/ui_xyz_off_icon.png b/textures/ui_xyz_off_icon.png
deleted file mode 100644
index 3c1836e..0000000
Binary files a/textures/ui_xyz_off_icon.png and /dev/null differ
diff --git a/textures/ui_xyz_on_icon.png b/textures/ui_xyz_on_icon.png
deleted file mode 100644
index 003ea63..0000000
Binary files a/textures/ui_xyz_on_icon.png and /dev/null differ
diff --git a/waypoints.lua b/waypoints.lua
index e23ef4b..cb1bafe 100644
--- a/waypoints.lua
+++ b/waypoints.lua
@@ -244,4 +244,3 @@ end)
 minetest.register_on_leaveplayer(function(player)
 	waypoints_temp[player:get_player_name()] = nil
 end)
-