diff --git a/README.md b/README.md
index 5f263f1..25905f8 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ Or just use /giveme replacer:replacer
 
 Usage: Right-click on a node of that type you want to replace other nodes with.
        Left-click (normal usage) on any nodes you want to replace with the type you previously right-clicked on.
-       SHIFT-Right-click in order to store a new pattern.
+       Sneak-Right-click (alternatively: aux1-Right-click) in order to store a new pattern.
 
 When in creative mode, the node will just be replaced. Your inventory will not be changed.
 
diff --git a/depends.txt b/depends.txt
index fef1434..fe0f5de 100644
--- a/depends.txt
+++ b/depends.txt
@@ -1,2 +1,5 @@
 default?
 dye?
+moreblocks?
+stairs?
+stairsplus?
diff --git a/fs_history.lua b/fs_history.lua
new file mode 100644
index 0000000..cbe83be
--- /dev/null
+++ b/fs_history.lua
@@ -0,0 +1,206 @@
+-- apart from the history, the formspec also handles mode switches
+
+-- how many patterns are stored in the history? those don't take up much space,
+-- but a too long list might not be overly helpful for the players either
+replacer.max_hist_size = 20
+
+
+-- turn stored pattern string (<node_name> <param1> <param2>) into something readable by human beeings
+replacer.human_readable_pattern = function(pattern)
+	if(not(pattern)) then
+		return "(nothing)"
+	end
+	-- data is stored in the form "<nodename> <param1> <param2>"
+	local parts = string.split(pattern, " ")
+	if(not(parts) or #parts < 3) then
+		return "(corrupted data)"
+	end
+	local node_name = parts[1]
+	local param2 = parts[3]
+
+	local def = minetest.registered_nodes[ node_name ]
+	if(not(def)) then
+		return "(unknown node)"
+	end
+	local text = "'"..tostring(def.description or "- no description -").."'"
+	if(not(def.description) or def.description == "") then
+		text = "- no description -"
+	end
+	-- facedir is probably the most commonly used rotation variant
+	if( def.paramtype2 == "facedir"
+	 or def.paramtype2 == "colorfacedir") then
+		local axis_names = {"y+ (Ground)", "z+ (North)", "z- (South)",
+				    "x+ (East)", "x- (West)", "y- (Sky)"}
+		text = text.." Rotated: "..tostring(param2 % 4)..
+			" around axis: "..tostring( axis_names[ math.floor( (param2%24) / 4 ) + 1 ])
+	-- wallmounted is diffrent
+	elseif( def.paramtype2 == "wallmounted"
+	     or def.paramtype2 == "colorwallmounted") then
+		local axis_names = {"y+ (Ground)", "y- (Sky)",
+				    "z+ (North)", "z- (South)",
+				    "x+ (East)", "x- (West)"}
+		text = text.." Mounted at wall: "..tostring( axis_names[ (param2 % 6)+ 1 ])
+	end
+	return text
+end
+
+
+-- set the replacer to a new pattern
+replacer.set_to = function(player_name, pattern, player, itemstack)
+	if(not(player_name) or not(player) or not(itemstack)) then
+		return itemstack
+	end
+	-- fallback if nothing is given
+	if(not(pattern)) then
+		pattern = "default:dirt 0 0"
+	end
+
+	local set_to = replacer.human_readable_pattern(pattern)
+	-- change the description of the tool so that it's easier to see which replacer (if you
+	-- have more than one in your inv) is set to which node
+	local meta = itemstack:get_meta()
+	-- actually store the new pattern
+	meta:set_string("pattern", pattern )
+
+	meta:set_string("description", "Node replacement tool set to:\n"..set_to..
+					"\n["..tostring(pattern).."]")
+
+	minetest.chat_send_player(player_name, "Node replacement tool set to: "..set_to..
+					"["..tostring(pattern).."].")
+
+	replacer.add_to_hist(player_name, pattern)
+	return itemstack -- nothing consumed but data changed
+end
+
+
+-- keep a history of stored patterns for each player (not for each replacer);
+-- this history is not saved over server shutdown
+replacer.add_to_hist = function(player_name, pattern)
+	if(not(player_name) or not(pattern) or pattern == "") then
+		return
+	end
+	if(not(replacer.history)) then
+		replacer.history = {}
+	end
+	if(not(replacer.history[ player_name ])) then
+		replacer.history[ player_name ] = {}
+	end
+	local index = table.indexof(replacer.history[ player_name ], pattern)
+	-- only add new entries; do not store duplicates
+	if(index and index > -1) then
+		return
+	end
+	-- remove the oldest entry
+	if(#replacer.history[ player_name ] >= replacer.max_hist_size) then
+		table.remove(replacer.history[ player_name ], 1)
+	end
+	table.insert(replacer.history[ player_name ], pattern)
+end
+
+
+-- show a formspec with a history of stored patterns to select from
+replacer.get_formspec = function(player_name, current_pattern, player)
+	-- is the player in creative mode?
+	local in_creative_mode = (minetest.settings:get_bool("creative_mode")
+				or minetest.check_player_privs(player_name, {creative=true}))
+	-- count how many blocks of each type the player has in his inventory
+	local counted_inv = {}
+	if(not(in_creative_mode)) then
+		local inv_main = player:get_inventory():get_list("main")
+		for i, v in ipairs(inv_main) do
+			local stack_name = v:get_name()
+			if(not(counted_inv[ stack_name ])) then
+				counted_inv[ stack_name ] = 0
+			end
+			counted_inv[ stack_name ] = counted_inv[ stack_name ] + v:get_count()
+		end
+	end
+
+	-- find out which mode the player has currently selected
+	local current_mode = 1
+	if(replacer.user_mode and replacer.user_mode[ player_name ]) then
+		current_mode = table.indexof(replacer.mode_names, replacer.user_mode[ player_name ])
+		if(current_mode == -1) then
+			current_mode = 1
+		end
+	end
+
+	local formspec = "size[18,10]"..
+		"label[6,0;Node Replacement Tool Setup and History]"..
+		"button_exit[8,9.4;2,0.8;quit;Exit]"..
+		"label[0.2,8.5;Note: Selected mode and history are reset on server restart.\n"..
+			"Note: The selected mode is valid for *all* replacers you use. "..
+			"The stored pattern is valid for *this particular* replacer only.]"..
+		"label[0.2,0.6;Select mode: When replacing (punching, left-click) or "..
+			"placing (right-click) a block, ..]"..
+		"dropdown[0.2,1.0;17;select_mode;"..
+			table.concat(replacer.mode_descriptions, ",")..
+			";"..tostring(current_mode)..";]"..
+		"label[0.2,2.1;Click here to set the replacer to a pattern you have stored before:]"..
+		"tablecolumns[color;"..
+			"text,align=right,tooltip=Amount of nodes of this type left in your inventory:"..
+			";color;text,align=left,tooltip=Stored pattern:]"..
+		"table[0.2,2.5;17,6;replacer_history;"
+	-- make sure all variables exist and the current entry is stored
+	replacer.add_to_hist(player_name, current_pattern)
+	local hist_entries = {}
+	local selected = 1
+	for i, v in ipairs(replacer.history[ player_name ]) do
+		if(v == current_pattern) then
+			selected = i
+		end
+		local amount_left = "#00FF00,infinite supply:,#00FF00"
+		if(not(in_creative_mode)) then
+			-- which item are we looking for?
+			local parts = v:split(" ")
+			if(not(parts) or #parts<1) then
+				parts = {"does not exist"}
+			-- TODO: handle this in a more general way
+			elseif(parts[1] == "default:dirt_with_grass") then
+				parts[1] = "default:dirt"
+			end
+			if(counted_inv[ parts[1] ]) then
+				amount_left = "#00FF00,"..tostring(counted_inv[ parts[1] ]).." available:"..
+					",#00FF00"
+			else
+				amount_left = "#FF0000,none left!,#CFCFCF"
+			end
+		end
+		hist_entries[ i ] = tostring(amount_left)..","..
+			minetest.formspec_escape(replacer.human_readable_pattern(v).." ["..v.."]")
+	end
+	return formspec..table.concat(hist_entries, ",")..";"..tostring(selected).."]"
+end
+
+
+-- the player has interacted with our formspec
+minetest.register_on_player_receive_fields( function(player, formname, fields)
+	if(not(formname) or formname ~= "replacer:menu") then
+		return false
+	end
+	local player_name = player:get_player_name()
+	-- the player clicked on an entry in the history
+	if(fields and fields.replacer_history
+	   and replacer.history and replacer.history[ player_name ]) then
+		-- find out which line it was
+		local selected = minetest.explode_table_event(fields.replacer_history)
+		if(selected and (selected.type == "CHG" or selected.type == "DLC")
+		   and selected.row <= #replacer.history[ player_name ]) then
+			local itemstack = player:get_wielded_item()
+			itemstack = replacer.set_to(player_name,
+				replacer.history[ player_name ][ selected.row ],
+				player, itemstack)
+			player:set_wielded_item(itemstack)
+			return true
+		end
+	end
+	-- the player selected a mode
+	if(fields and fields.select_mode) then
+		local index = table.indexof(replacer.mode_descriptions,
+				minetest.formspec_escape(fields.select_mode))
+		if(index and index > -1 and replacer.mode_names[ index ]) then
+			replacer.user_mode[ player_name ] = replacer.mode_names[ index ]
+		end
+	end
+	return true
+end)
diff --git a/init.lua b/init.lua
index bfecb8c..c1aa311 100644
--- a/init.lua
+++ b/init.lua
@@ -21,6 +21,12 @@
 -- Version 3.0
 
 -- Changelog: 
+-- 02.09.2021 * Added a history of stored patterns (not saved over server restart)
+--            * Added a menu to select a history entry. It is accessable via AUX1 + left click.
+--            * Removed deprecated functions get/set_metadata(..) and renamed metadata to pattern
+-- 29.09.2021 * AUX1 key works now same as SNEAK key for storing new pattern (=easier when flying)
+--            * The description of the tool now shows which pattern is stored
+--            * The description of the stored pattern is more human readable
 -- 09.12.2017 * Got rid of outdated minetest.env
 --            * Fixed error in protection function.
 --            * Fixed minor bugs.
@@ -58,6 +64,13 @@ replacer.blacklist[ "protector:protect2"] = true;
 -- adds a tool for inspecting nodes and entities
 dofile(minetest.get_modpath("replacer").."/inspect.lua");
 
+-- adds a formspec with a history function (accessible with AUX1 + left click)
+dofile(minetest.get_modpath("replacer").."/fs_history.lua");
+
+-- adds support for the circular saw from moreblocks and similar nodes
+-- and allows to replace the *material* while keeping shape - or vice versa
+dofile(minetest.get_modpath("replacer").."/mode_of_replacement.lua");
+
 minetest.register_tool( "replacer:replacer",
 {
     description = "Node replacement tool",
@@ -81,7 +94,6 @@ minetest.register_tool( "replacer:replacer",
     },
 --]]
     node_placement_prediction = nil,
-    metadata = "default:dirt", -- default replacement: common dirt
 
     on_place = function(itemstack, placer, pointed_thing)
 
@@ -93,8 +105,8 @@ minetest.register_tool( "replacer:replacer",
 
        local keys=placer:get_player_control();
     
-       -- just place the stored node if now new one is to be selected
-       if( not( keys["sneak"] )) then
+       -- just place the stored node if no new one is to be selected
+       if( not( keys["sneak"] ) and not( keys["aux1"])) then
 
           return replacer.replace( itemstack, placer, pointed_thing, true  ); end
 
@@ -104,24 +116,18 @@ minetest.register_tool( "replacer:replacer",
           return nil;
        end
 
-       local pos  = minetest.get_pointed_thing_position( pointed_thing, false );
+       local pos  = minetest.get_pointed_thing_position( pointed_thing, false ); -- node under
        local node = minetest.get_node_or_nil( pos );
        
-       --minetest.chat_send_player( name, "  Target node: "..minetest.serialize( node ).." at pos "..minetest.serialize( pos ).."."); 
-       local metadata = "default:dirt 0 0";
+       local pattern = "default:dirt 0 0";
        if( node ~= nil and node.name ) then
-          metadata = node.name..' '..node.param1..' '..node.param2;
+          pattern = node.name..' '..node.param1..' '..node.param2;
        end
-       itemstack:set_metadata( metadata );
 
-       minetest.chat_send_player( name, "Node replacement tool set to: '"..metadata.."'.");
-
-       return itemstack; -- nothing consumed but data changed
+       return replacer.set_to(name, pattern, placer, itemstack) -- nothing consumed but data changed
     end,
      
 
---    on_drop = func(itemstack, dropper, pos),
-
     on_use = function(itemstack, user, pointed_thing)
 
        return replacer.replace( itemstack, user, pointed_thing, false );
@@ -135,7 +141,6 @@ replacer.replace = function( itemstack, user, pointed_thing, mode )
           return nil;
        end
        local name = user:get_player_name();
-       --minetest.chat_send_player( name, "You USED this on "..minetest.serialize( pointed_thing )..".");
  
        if( pointed_thing.type ~= "node" ) then
           minetest.chat_send_player( name, "  Error: No node.");
@@ -145,8 +150,6 @@ replacer.replace = function( itemstack, user, pointed_thing, mode )
        local pos  = minetest.get_pointed_thing_position( pointed_thing, mode );
        local node = minetest.get_node_or_nil( pos );
        
-       --minetest.chat_send_player( name, "  Target node: "..minetest.serialize( node ).." at pos "..minetest.serialize( pos ).."."); 
-
        if( node == nil ) then
 
           minetest.chat_send_player( name, "Error: Target node not yet loaded. Please wait a moment for the server to catch up.");
@@ -154,15 +157,22 @@ replacer.replace = function( itemstack, user, pointed_thing, mode )
        end
 
 
-       local item = itemstack:to_table();
+       local meta = itemstack:get_meta()
+       local pattern = meta:get_string("pattern")
 
        -- make sure it is defined
-       if( not( item[ "metadata"] ) or item["metadata"]=="" ) then
-          item["metadata"] = "default:dirt 0 0";
+       if(not(pattern) or pattern == "") then
+          pattern = "default:dirt 0 0";
+       end
+
+       local keys=user:get_player_control();
+       if( keys["aux1"]) then
+           minetest.show_formspec(name, "replacer:menu", replacer.get_formspec(name, pattern, user))
+           return nil
        end
 
        -- regain information about nodename, param1 and param2
-       local daten = item[ "metadata"]:split( " " );
+       local daten = pattern:split( " " );
        -- the old format stored only the node name
        if( #daten < 3 ) then
           daten[2] = 0;
@@ -175,6 +185,12 @@ replacer.replace = function( itemstack, user, pointed_thing, mode )
           return nil;
        end
 
+       local daten = replacer.get_new_node_data(node, daten, name)
+       -- nothing to replace
+       if(not(daten)) then
+          return
+       end
+
        if( node.name and node.name ~= "" and replacer.blacklist[ node.name ]) then
           minetest.chat_send_player( name, "Replacing blocks of the type '"..( node.name or "?" )..
 		"' is not allowed on this server. Replacement failed.");
@@ -198,7 +214,6 @@ replacer.replace = function( itemstack, user, pointed_thing, mode )
           return nil;
        end
 
-
        -- in survival mode, the player has to provide the node he wants to place
        if( not(minetest.settings:get_bool("creative_mode") )
 	  and not( minetest.check_player_privs( name, {creative=true}))) then
@@ -207,7 +222,7 @@ replacer.replace = function( itemstack, user, pointed_thing, mode )
           -- fortunately, dirt and dirt_with_grass does not make use of rotation
           if( daten[1] == "default:dirt_with_grass" ) then
              daten[1] = "default:dirt";
-             item["metadata"] = "default:dirt 0 0";
+             pattern = "default:dirt 0 0";
           end
 
           -- does the player carry at least one of the desired nodes with him?
@@ -219,20 +234,9 @@ replacer.replace = function( itemstack, user, pointed_thing, mode )
           end
 
 
-
           -- give the player the item by simulating digging if possible
-          if(   node.name ~= "air"
-						 and node.name ~= "ignore"
-						 and node.name ~= "default:lava_source" 
-						 and node.name ~= "default:lava_flowing"
-						 and node.name ~= "default:river_water_source"
-						 and node.name ~= "default:river_water_flowing"
-						 and node.name ~= "default:water_source"
-						 and node.name ~= "default:water_flowing"
-						 and node.name ~= "nalc:acid_source"
-						 and node.name ~= "nalc:acid_flowing"
-						 and node.name ~= "nalc:sand_source"
-						 and node.name ~= "nalc:sand_flowing" ) then
+          if(   node.name ~= "air" 
+            and node.name ~= "ignore") then
 
              minetest.node_dig( pos, node, user );
 
@@ -240,21 +244,20 @@ replacer.replace = function( itemstack, user, pointed_thing, mode )
              if( not( digged_node ) 
                 or digged_node.name == node.name ) then
 
-                minetest.chat_send_player( name, "Replacing '"..( node.name or "air" ).."' with '"..( item[ "metadata"] or "?" ).."' failed. Unable to remove old node.");
-                return nil;
+                -- some nodes - like liquids - cannot be digged. but they are buildable_to and
+                -- thus can be replaced
+                local node_def = minetest.registered_nodes[node.name]
+                if(not(node_def) or not(node_def.buildable_to)) then
+                   minetest.chat_send_player( name, "Replacing '"..( node.name or "air" ).."' with '"..( pattern or "?" ).."' failed. Unable to remove old node.");
+                   return nil;
+                end
              end
             
           end
 
           -- consume the item
           user:get_inventory():remove_item("main", daten[1].." 1");
-
-          --user:get_inventory():add_item( "main", node.name.." 1");
        end
-
-       --minetest.chat_send_player( name, "Replacing node '"..( node.name or "air" ).."' with '"..( item[ "metadata"] or "?" ).."'.");
-
-       --minetest.place_node( pos, { name =  item[ "metadata" ] } );
        minetest.add_node( pos, { name =  daten[1], param1 = daten[2], param2 = daten[3] } );
        return nil; -- no item shall be removed from inventory
     end
diff --git a/inspect.lua b/inspect.lua
index bfc89d8..a0efced 100644
--- a/inspect.lua
+++ b/inspect.lua
@@ -58,7 +58,7 @@ replacer.inspect = function( itemstack, user, pointed_thing, mode, show_receipe
 	end
 	local name = user:get_player_name();
 	local keys = user:get_player_control();
-	if( keys["sneak"] ) then
+	if( keys["sneak"] or keys["aux1"]) then
 		show_receipe = true;
 	end
  
diff --git a/mod.conf b/mod.conf
new file mode 100644
index 0000000..f642ade
--- /dev/null
+++ b/mod.conf
@@ -0,0 +1,5 @@
+name = replacer
+description = Essential tool for builders. Allows to store material and rotation and place more blocks the same way without having to turn them all individually with the screwdriver.
+optional_depends = default, dye, moreblocks, stairs, stairsplus
+author = Sokomine
+title = Replacer - Node Replace Tool
diff --git a/mode_of_replacement.lua b/mode_of_replacement.lua
new file mode 100644
index 0000000..5633d27
--- /dev/null
+++ b/mode_of_replacement.lua
@@ -0,0 +1,226 @@
+
+-- store for each user which mode the user has selected
+replacer.user_mode = {}
+
+-- descriptions for the dropdown menu (accessible via AUX1 + left-click)
+replacer.mode_descriptions = {
+	"[ normal ] replace material, shape and orientation according to the stored pattern",
+	"[ material ] replace the material only (if possible), but keep shape and orientation",
+	"[ shape ] replace shape and orientation (if possible), but keep the material"}
+
+-- internal names for the above modes (will be stored in replacer.user_mode[ player_name ])
+replacer.mode_names = {"normal", "material", "shape"}
+
+-- make sure all mode descriptions are properly escaped for the dropdown menu
+for i, v in ipairs(replacer.mode_descriptions) do
+	replacer.mode_descriptions[i] = minetest.formspec_escape(v)
+end
+
+-- sometimes some few node names for on or two materials do not follow the
+-- pattern of node names for that type; offer a way to translate them here
+replacer.node_name_alternatives = {}
+replacer.node_name_alternatives[ "default:mese_post_light_wood" ] = "default:mese_post_light"
+replacer.node_name_alternatives[ "walls:desert_cobble" ] = "walls:desertcobble"
+
+-- support for the circular saw; table contains prefixes as indices plus
+-- a list of known suffixes for that prefix 
+replacer.saw_prefixes = {}
+
+-- populate replacer.saw_prefixes
+if(minetest.global_exists("circular_saw") and circular_saw.names) then
+	-- this is fixed for the saw and does not depend on which actual nodes are
+	-- registered for it later on;
+	-- we build this table replacer.saw_prefixes for faster lookup because
+	-- many shapes share the same prefix
+	for i, v in ipairs(circular_saw.names) do
+		local prefix = v[1].."_"
+		if(not(replacer.saw_prefixes[ prefix ])) then
+			replacer.saw_prefixes[ prefix ] = {v[2]}
+		else
+			table.insert(replacer.saw_prefixes[ prefix ], v[2])
+		end
+	end
+end
+
+
+-- functions
+
+-- does node_name match any name from the circular saw?
+-- or is it a node from the cnc machine?
+-- and if so, which material is it?
+-- returns: {created_by_machine, source node name, mod_name, prefix, material, suffix}
+--          (the last four form the name of the node)
+replacer.identify_shape_and_material = function(full_node_name)
+	local parts = full_node_name:split(":")
+	if(not(parts) or #parts < 2) then
+		return nil
+	end
+	local mod_name = parts[1]
+	local node_name = parts[2]
+
+	-- it might be a full block - or any other drawtype not really covered here
+	local def = minetest.registered_nodes[ full_node_name ]
+	if(def and def.drawtype and def.drawtype == "normal") then
+		return {"normal", full_node_name,
+			mod_name, "", node_name, ""}
+	end
+
+	-- a wooden fence rail
+	local prefix = "fence_rail_"
+	if(mod_name == "default" and node_name:sub(1, #prefix) == prefix) then
+		local material = node_name:sub(#prefix + 1)
+		return {"fence_rail", "default:"..material, "default", prefix, material, ""}
+	end
+	-- a wooden fence
+	prefix = "fence_"
+	if(mod_name == "default" and node_name:sub(1, #prefix) == prefix) then
+		local material = node_name:sub(#prefix + 1)
+		return {"fence", "default:"..material, "default", prefix, material, ""}
+	end
+	-- gates come in diffrent wood types as well
+	prefix = "gate_"
+	if(mod_name == "doors" and node_name:sub(1, #prefix) == prefix) then
+		local gate_suffixes = {"_open", "_closed"}
+		for i, suffix in ipairs(gate_suffixes) do
+			if(node_name:sub(-#suffix) == suffix) then
+				local material = node_name:sub(#prefix+1, -#suffix-1)
+				return {"gate", "default:"..material, "doors", prefix, material, suffix}
+			end
+		end
+	end
+	-- a mese post (comes in diffrent wood types)
+	prefix = "mese_post_light_"
+	if(full_node_name == "default:mese_post_light") then
+		return {"mese_post", "default:wood", "default", "mese_post_light_", "", ""}
+	elseif(mod_name == "default" and node_name:sub(1, #prefix) == prefix) then
+		local material = node_name:sub(#prefix + 1)
+		return {"mese_post", "default:"..material, "default", prefix, material, ""}
+	end
+	-- walls (usually made out of stone)
+	if(full_node_name == "walls:cobble") then
+		return {"walls", "default:cobble", "walls", "", "cobble", ""}
+	elseif(full_node_name == "walls:mossycobble") then
+		return {"walls", "default:mossycobble", "walls", "", "mossycobble", ""}
+	elseif(full_node_name == "walls:desertcobble") then
+		return {"walls", "default:desert_cobble", "walls", "", "desert_cobble", ""}
+	end
+
+	-- it might be a regular stair (or similar node) from MinetestGame's stair mod
+	if(mod_name == "stairs") then
+		-- stair_inner_ and stair_outer_ need to be checked before stair_ is checked
+		-- because they are more specific
+		local stair_prefixes = {"stair_inner_", "stair_outer_", "stair_", "slab_"}
+		for i, prefix in ipairs(stair_prefixes) do
+			if(node_name:sub(1,#prefix) == prefix) then
+				local material = node_name:sub(#prefix+1)
+				return {"stairs", "default:"..material,
+					mod_name, prefix, material, ""}
+			end
+		end
+		return nil
+	end
+
+	-- check if we are dealing with a node from the circular saw from moreblocks
+	for prefix, suffixes in pairs(replacer.saw_prefixes) do
+		-- the prefix matches; does any suffix match?
+		if(node_name:sub(1, #prefix) == prefix) then
+			for i, suffix in ipairs(suffixes) do
+				if(suffix == "" or node_name:sub(-#suffix) == suffix) then
+					local material = node_name:sub(#prefix + 1, -#suffix-1)
+					for m_name, m_parts in pairs(circular_saw.known_nodes) do
+						if(m_parts[2] == material) then
+							return {"circular_saw", m_name,
+								m_parts[1], prefix, material, suffix}
+						end
+					end
+				end
+			end
+			-- no need to check the other prefixes; they won't match either
+			return ""
+		end
+	end
+
+	-- check if we are dealing with a node from the cnc machine
+	if(minetest.global_exists("technic_cnc") and technic_cnc.programs) then
+		for i, data in ipairs(technic_cnc.programs) do
+			if(full_node_name:sub(-#data.suffix-1) == "_"..data.suffix) then
+				local source_node = full_node_name:sub(1,-#data.suffix-2)
+				local p = source_node:split(":")
+				return {"tecnic_cnc", source_node,
+					p[1], "", p[2], "_"..data.suffix}
+			end
+		end
+	end
+
+	-- TODO: pkarcs, mymillworks etc. mods, pillars, castle, ..
+	return nil
+end
+
+
+-- try to convert the old node into the desired new node
+-- the mode is stored in replacer.user_mode[ player_name ] (fallback: normal)
+replacer.get_new_node_data = function(old_node, stored_pattern, player_name)
+	if(not(old_node) or not(stored_pattern) or not(old_node.name)) then
+		return nil
+	end
+
+	-- normal mode of operation: replace material, shape and orientation
+	if(not(replacer.user_mode)
+	  or not(replacer.user_mode[ player_name ])
+	  or replacer.user_mode[ player_name ] == "normal") then
+		return stored_pattern
+	end
+
+	-- what type of node does the stored pattern represent? 
+	local new_data = replacer.identify_shape_and_material(stored_pattern[1])
+	-- if the type of the stored pattern cannot be identified, then abort here
+	if(not(new_data)) then
+		return nil
+	end
+	local old_data = replacer.identify_shape_and_material(old_node.name)
+	-- if the type of the node that is to be replaced cannot be identified, then abort here
+	if(not(old_data)) then
+		return nil
+	end
+
+	-- replace material, but keep shape and orientation
+	if(replacer.user_mode[ player_name ] == "material") then
+		-- now try to replace the *material* of the old node while keeping prefix and postfix
+		local new_name = old_data[3]..":"..old_data[4]..new_data[5]..old_data[6]
+		-- handle some exceptions like mese post light wood and desert_cobble walls
+		if(not(minetest.registered_nodes[ new_name ])
+		  and replacer.node_name_alternatives[ new_name ]) then
+			new_name = replacer.node_name_alternatives[ new_name ]
+		end
+		-- perhaps we need to change the mod name to the new material as well
+		if(not(minetest.registered_nodes[ new_name ])) then
+			new_name = new_data[3]..":"..old_data[4]..new_data[5]..old_data[6]
+		end
+		-- if the node still doesn't exist: give up
+		if(not(minetest.registered_nodes[ new_name ])) then
+			return nil
+		end
+		-- keep param1 and param2, but change the node name
+		return {new_name, old_node.param1, old_node.param2}
+
+	-- replace shape and orientation, but keep material
+	elseif(replacer.user_mode[ player_name ] == "shape") then
+		-- now try to replace the *material* of the old node while keeping prefix and postfix
+		local new_name = new_data[3]..":"..new_data[4]..old_data[5]..new_data[6]
+		-- handle some exceptions like mese post light wood and desert_cobble walls
+		if(not(minetest.registered_nodes[ new_name ])
+		  and replacer.node_name_alternatives[ new_name ]) then
+			new_name = replacer.node_name_alternatives[ new_name ]
+		end
+		-- perhaps we need to change the mod name to the new material as well
+		if(not(minetest.registered_nodes[ new_name ])) then
+			new_name = old_data[3]..":"..new_data[4]..old_data[5]..new_data[6]
+		end
+		-- if the node still doesn't exist: give up
+		if(not(minetest.registered_nodes[ new_name ])) then
+			return nil
+		end
+		-- keep material, but change shape and orientation
+		return {new_name, stored_pattern[2], stored_pattern[3]}
+	end
+end