diff --git a/clams/init.lua b/clams/init.lua
index 9c6cb3f..688e334 100644
--- a/clams/init.lua
+++ b/clams/init.lua
@@ -160,8 +160,8 @@ minetest.register_ore({
 	clust_scarcity = 9*9*9,
 	clust_num_ores = 16,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -60,
+	y_max     = -4,
+	y_min     = -60,
 })
 
 minetest.register_ore({
@@ -171,17 +171,17 @@ minetest.register_ore({
 	clust_scarcity = 9*9*9,
 	clust_num_ores = 16,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -60,
+	y_max     = -4,
+	y_min     = -60,
 })
 
 
-local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, chunk_size, ore_per_chunk, height_min, height_max)
-	if maxp.y < height_min or minp.y > height_max then
+local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, chunk_size, ore_per_chunk, y_min, y_max)
+	if maxp.y < y_min or minp.y > y_max then
 		return
 	end
-	local y_min = math.max(minp.y, height_min)
-	local y_max = math.min(maxp.y, height_max)
+	local y_min = math.max(minp.y, y_min)
+	local y_max = math.min(maxp.y, y_max)
 	if chunk_size >= y_max - y_min + 1 then
 		return
 	end
@@ -191,7 +191,7 @@ local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume,
 	local inverse_chance = math.floor(chunk_size*chunk_size*chunk_size / ore_per_chunk)
 	for i=1,num_chunks do
 		local y0 = pr:next(y_min, y_max-chunk_size+1)
-		if y0 >= height_min and y0 <= height_max then
+		if y0 >= y_min and y0 <= y_max then
 			local x0 = pr:next(minp.x, maxp.x-chunk_size+1)
 			local z0 = pr:next(minp.z, maxp.z-chunk_size+1)
 			local p0 = {x=x0, y=y0, z=z0}
diff --git a/seacoral/init.lua b/seacoral/init.lua
index 2aa6d7d..bee5bb6 100644
--- a/seacoral/init.lua
+++ b/seacoral/init.lua
@@ -260,8 +260,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
 minetest.register_ore({
@@ -271,8 +271,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
 minetest.register_ore({
@@ -282,8 +282,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
 minetest.register_ore({
@@ -293,8 +293,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
 minetest.register_ore({
@@ -304,8 +304,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
 minetest.register_ore({
@@ -315,8 +315,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
 minetest.register_ore({
@@ -326,8 +326,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
 minetest.register_ore({
@@ -337,8 +337,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
 minetest.register_ore({
@@ -348,8 +348,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
 minetest.register_ore({
@@ -359,8 +359,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
 minetest.register_ore({
@@ -370,8 +370,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
 minetest.register_ore({
@@ -381,16 +381,16 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -4,
-	height_min     = -8,
+	y_max     = -4,
+	y_min     = -8,
 })
 
-local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, chunk_size, ore_per_chunk, height_min, height_max)
-	if maxp.y < height_min or minp.y > height_max then
+local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, chunk_size, ore_per_chunk, y_min, y_max)
+	if maxp.y < y_min or minp.y > y_max then
 		return
 	end
-	local y_min = math.max(minp.y, height_min)
-	local y_max = math.min(maxp.y, height_max)
+	local y_min = math.max(minp.y, y_min)
+	local y_max = math.min(maxp.y, y_max)
 	if chunk_size >= y_max - y_min + 1 then
 		return
 	end
@@ -400,7 +400,7 @@ local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume,
 	local inverse_chance = math.floor(chunk_size*chunk_size*chunk_size / ore_per_chunk)
 	for i=1,num_chunks do
 		local y0 = pr:next(y_min, y_max-chunk_size+1)
-		if y0 >= height_min and y0 <= height_max then
+		if y0 >= y_min and y0 <= y_max then
 			local x0 = pr:next(minp.x, maxp.x-chunk_size+1)
 			local z0 = pr:next(minp.z, maxp.z-chunk_size+1)
 			local p0 = {x=x0, y=y0, z=z0}
diff --git a/seaplants/init.lua b/seaplants/init.lua
index b9bc837..9130e82 100644
--- a/seaplants/init.lua
+++ b/seaplants/init.lua
@@ -228,8 +228,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -14,
-	height_min     = -31000,
+	y_max     = -14,
+	y_min     = -31000,
 })
 
 minetest.register_ore({
@@ -239,8 +239,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -14,
-	height_min     = -31000,
+	y_max     = -14,
+	y_min     = -31000,
 })
 
 minetest.register_ore({
@@ -250,8 +250,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -14,
-	height_min     = -31000,
+	y_max     = -14,
+	y_min     = -31000,
 })
 
 minetest.register_ore({
@@ -261,8 +261,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -14,
-	height_min     = -31000,
+	y_max     = -14,
+	y_min     = -31000,
 })
 
 minetest.register_ore({
@@ -272,8 +272,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -14,
-	height_min     = -31000,
+	y_max     = -14,
+	y_min     = -31000,
 })
 
 minetest.register_ore({
@@ -283,8 +283,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -14,
-	height_min     = -31000,
+	y_max     = -14,
+	y_min     = -31000,
 })
 
 minetest.register_ore({
@@ -294,8 +294,8 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -14,
-	height_min     = -31000,
+	y_max     = -14,
+	y_min     = -31000,
 })
 
 minetest.register_ore({
@@ -305,16 +305,16 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 24,
 	clust_size     = 4,
-	height_max     = -14,
-	height_min     = -31000,
+	y_max     = -14,
+	y_min     = -31000,
 })
 
-local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, chunk_size, ore_per_chunk, height_min, height_max)
-	if maxp.y < height_min or minp.y > height_max then
+local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, chunk_size, ore_per_chunk, y_min, y_max)
+	if maxp.y < y_min or minp.y > y_max then
 		return
 	end
-	local y_min = math.max(minp.y, height_min)
-	local y_max = math.min(maxp.y, height_max)
+	local y_min = math.max(minp.y, y_min)
+	local y_max = math.min(maxp.y, y_max)
 	if chunk_size >= y_max - y_min + 1 then
 		return
 	end
@@ -324,7 +324,7 @@ local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume,
 	local inverse_chance = math.floor(chunk_size*chunk_size*chunk_size / ore_per_chunk)
 	for i=1,num_chunks do
 		local y0 = pr:next(y_min, y_max-chunk_size+1)
-		if y0 >= height_min and y0 <= height_max then
+		if y0 >= y_min and y0 <= y_max then
 			local x0 = pr:next(minp.x, maxp.x-chunk_size+1)
 			local z0 = pr:next(minp.z, maxp.z-chunk_size+1)
 			local p0 = {x=x0, y=y0, z=z0}
diff --git a/seawrecks/init.lua b/seawrecks/init.lua
index 65c888e..103eeb0 100644
--- a/seawrecks/init.lua
+++ b/seawrecks/init.lua
@@ -124,8 +124,8 @@ minetest.register_ore({
 	clust_scarcity = 30*30*30,
 	clust_num_ores = 1,
 	clust_size     = 12,
-	height_max     = -4,
-	height_min     = -31000,
+	y_max     = -4,
+	y_min     = -31000,
 })
 
 minetest.register_ore({
@@ -135,16 +135,16 @@ minetest.register_ore({
 	clust_scarcity = 30*30*30,
 	clust_num_ores = 1,
 	clust_size     = 12,
-	height_max     = -8,
-	height_min     = -31000,
+	y_max     = -8,
+	y_min     = -31000,
 })
 
-local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, chunk_size, ore_per_chunk, height_min, height_max)
-	if maxp.y < height_min or minp.y > height_max then
+local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, chunk_size, ore_per_chunk, y_min, y_max)
+	if maxp.y < y_min or minp.y > y_max then
 		return
 	end
-	local y_min = math.max(minp.y, height_min)
-	local y_max = math.min(maxp.y, height_max)
+	local y_min = math.max(minp.y, y_min)
+	local y_max = math.min(maxp.y, y_max)
 	if chunk_size >= y_max - y_min + 1 then
 		return
 	end
@@ -154,7 +154,7 @@ local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume,
 	local inverse_chance = math.floor(chunk_size*chunk_size*chunk_size / ore_per_chunk)
 	for i=1,num_chunks do
 		local y0 = pr:next(y_min, y_max-chunk_size+1)
-		if y0 >= height_min and y0 <= height_max then
+		if y0 >= y_min and y0 <= y_max then
 			local x0 = pr:next(minp.x, maxp.x-chunk_size+1)
 			local z0 = pr:next(minp.z, maxp.z-chunk_size+1)
 			local p0 = {x=x0, y=y0, z=z0}
diff --git a/whiteshell/init.lua b/whiteshell/init.lua
index ffc10ac..f34c347 100644
--- a/whiteshell/init.lua
+++ b/whiteshell/init.lua
@@ -32,17 +32,17 @@ minetest.register_ore({
 	clust_scarcity = 10*10*10,
 	clust_num_ores = 18,
 	clust_size     = 6,
-	height_max     = 31000,
-	height_min     = -31000,
+	y_max     = 31000,
+	y_min     = -31000,
 })
 
 
-local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, chunk_size, ore_per_chunk, height_min, height_max)
-	if maxp.y < height_min or minp.y > height_max then
+local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume, chunk_size, ore_per_chunk, y_min, y_max)
+	if maxp.y < y_min or minp.y > y_max then
 		return
 	end
-	local y_min = math.max(minp.y, height_min)
-	local y_max = math.min(maxp.y, height_max)
+	local y_min = math.max(minp.y, y_min)
+	local y_max = math.min(maxp.y, y_max)
 	if chunk_size >= y_max - y_min + 1 then
 		return
 	end
@@ -52,7 +52,7 @@ local function generate_ore(name, wherein, minp, maxp, seed, chunks_per_volume,
 	local inverse_chance = math.floor(chunk_size*chunk_size*chunk_size / ore_per_chunk)
 	for i=1,num_chunks do
 		local y0 = pr:next(y_min, y_max-chunk_size+1)
-		if y0 >= height_min and y0 <= height_max then
+		if y0 >= y_min and y0 <= y_max then
 			local x0 = pr:next(minp.x, maxp.x-chunk_size+1)
 			local z0 = pr:next(minp.z, maxp.z-chunk_size+1)
 			local p0 = {x=x0, y=y0, z=z0}