diff --git a/Documents/fielddatatypes.txt b/Documents/fielddatatypes.txt
index 53d0f2a0..3e95958a 100644
--- a/Documents/fielddatatypes.txt
+++ b/Documents/fielddatatypes.txt
@@ -23,8 +23,9 @@ all supported data types:
 
 - Only types indicates with * are usable for standard hexen args
 - When no type is specified, the default type is 0 (integer)
+- Enum types (11, 12 and 16) cannot be used in custom UDMF fields
 
-For types 11, 12 and 16 there must be an "enum" field that
+For enum types 11, 12 and 16 there must be an "enum" field that
 either specifies the values or refers to an existing enum set:
 
 	enum
@@ -37,7 +38,7 @@ either specifies the values or refers to an existing enum set:
 
 	enum = "yesno";
 
-Type 16 uses case-sensitive strings for value and can only be
+Type 16 uses case-sensitive strings for values and can only be
 used as an option, not as bit flags:
 
 	enum
diff --git a/Source/Builder.csproj b/Source/Builder.csproj
index 914dbe75..bae94b44 100644
--- a/Source/Builder.csproj
+++ b/Source/Builder.csproj
@@ -45,6 +45,7 @@
   </Target>
   -->
   <ItemGroup>
+    <Compile Include="Config\ArgumentInfo.cs" />
     <Compile Include="Config\EnumItem.cs" />
     <Compile Include="Config\EnumList.cs" />
     <Compile Include="Config\SectorEffectInfo.cs" />
@@ -117,6 +118,12 @@
     <Compile Include="Data\DataLocationList.cs" />
     <Compile Include="Data\DataManager.cs" />
     <Compile Include="Data\WADReader.cs" />
+    <Compile Include="Types\EnumOptionHandler.cs" />
+    <Compile Include="Types\IntegerHandler.cs" />
+    <Compile Include="Types\NullHandler.cs" />
+    <Compile Include="Types\TypeHandler.cs" />
+    <Compile Include="Types\TypeHandlerAttribute.cs" />
+    <Compile Include="Types\TypesManager.cs" />
     <Compile Include="Windows\AboutForm.cs">
       <SubType>Form</SubType>
     </Compile>
diff --git a/Source/Config/ArgumentInfo.cs b/Source/Config/ArgumentInfo.cs
new file mode 100644
index 00000000..c9285de7
--- /dev/null
+++ b/Source/Config/ArgumentInfo.cs
@@ -0,0 +1,109 @@
+
+#region ================== Copyright (c) 2007 Pascal vd Heiden
+
+/*
+ * Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
+ * This program is released under GNU General Public License
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ */
+
+#endregion
+
+#region ================== Namespaces
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+using CodeImp.DoomBuilder.IO;
+using CodeImp.DoomBuilder.Data;
+using System.IO;
+using System.Diagnostics;
+
+#endregion
+
+namespace CodeImp.DoomBuilder.Config
+{
+	public class ArgumentInfo
+	{
+		#region ================== Constants
+
+		#endregion
+
+		#region ================== Variables
+
+		private string title;
+		private bool used;
+		private int type;
+		private EnumList enumlist;
+
+		#endregion
+
+		#region ================== Properties
+
+		public string Title { get { return title; } }
+		public bool Used { get { return false; } }
+		public int Type { get { return type; } }
+		public EnumList Enum { get { return enumlist; } }
+
+		#endregion
+
+		#region ================== Constructor / Disposer
+
+		// Constructor for argument info from configuration
+		internal ArgumentInfo(Configuration cfg, string argspath, int argindex, IDictionary<string, EnumList> enums)
+		{
+			// Read
+			string istr = argindex.ToString(CultureInfo.InvariantCulture);
+			this.used = cfg.SettingExists(argspath + ".arg" + istr);
+			this.title = cfg.ReadSetting(argspath + ".arg" + istr + ".title", "Argument " + (argindex + 1));
+			this.type = cfg.ReadSetting(argspath + ".arg" + istr + ".type", 0);
+
+			// Determine enum type
+			EnumList enumlist = null;
+			IDictionary argdic = cfg.ReadSetting(argspath + ".arg" + istr, new Hashtable());
+			if(argdic.Contains("enum"))
+			{
+				// Enum fully specified?
+				if(argdic["enum"] is IDictionary)
+				{
+					// Create anonymous enum
+					this.enumlist = new EnumList(argdic["enum"] as IDictionary);
+				}
+				else
+				{
+					// Check if referenced enum exists
+					if((argdic["enum"].ToString().Length > 0) && enums.ContainsKey(argdic["enum"].ToString()))
+					{
+						// Get the enum list
+						this.enumlist = enums[argdic["enum"].ToString()] as EnumList;
+					}
+					else
+					{
+						General.WriteLogLine("WARNING: '" + argspath + ".arg" + istr + "' references unknown enumeration '" + argdic["enum"] + "'!");
+					}
+				}
+			}
+		}
+
+		#endregion
+
+		#region ================== Methods
+
+		// This gets the description for an argument value
+		public string GetValueDescription(int value)
+		{
+			// TODO: Use the registered type editor to get the description!
+
+			return value.ToString();
+		}
+
+		#endregion
+	}
+}
diff --git a/Source/Config/EnumItem.cs b/Source/Config/EnumItem.cs
index 65e22945..d5e92578 100644
--- a/Source/Config/EnumItem.cs
+++ b/Source/Config/EnumItem.cs
@@ -31,7 +31,7 @@ using System.Windows.Forms;
 
 namespace CodeImp.DoomBuilder.Config
 {
-	public class EnumItem : INumberedTitle
+	public class EnumItem
 	{
 		#region ================== Constants
 
@@ -39,14 +39,14 @@ namespace CodeImp.DoomBuilder.Config
 
 		#region ================== Variables
 
-		private int index;
+		private string value;
 		private string title;
 
 		#endregion
 
 		#region ================== Properties
 
-		public int Index { get { return index; } }
+		public string Value { get { return value; } }
 		public string Title { get { return title; } }
 
 		#endregion
@@ -54,10 +54,10 @@ namespace CodeImp.DoomBuilder.Config
 		#region ================== Constructor
 
 		// Constructor
-		public EnumItem(int index, string title)
+		public EnumItem(string value, string title)
 		{
 			// Initialize
-			this.index = index;
+			this.value = value;
 			this.title = title;
 		}
 		
@@ -71,6 +71,16 @@ namespace CodeImp.DoomBuilder.Config
 			return title;
 		}
 
+		// This returns the value as int
+		public int GetIntValue()
+		{
+			int result;
+			if(int.TryParse(value, NumberStyles.Integer, CultureInfo.InvariantCulture, out result))
+				return result;
+			else
+				return 0;
+		}
+		
 		#endregion
 	}
 }
diff --git a/Source/Config/EnumList.cs b/Source/Config/EnumList.cs
index 895f8d61..6aee13eb 100644
--- a/Source/Config/EnumList.cs
+++ b/Source/Config/EnumList.cs
@@ -39,43 +39,40 @@ namespace CodeImp.DoomBuilder.Config
 
 		#region ================== Variables
 
-		private string name;
-
 		#endregion
 
 		#region ================== Properties
 
-		public string Name { get { return name; } }
-
 		#endregion
 
 		#region ================== Constructor
 
+		// Constructor to load from dictionary
+		internal EnumList(IDictionary dic)
+		{
+			int index;
+
+			// Read the dictionary
+			foreach(DictionaryEntry de in dic)
+			{
+				// Add item
+				EnumItem item = new EnumItem(de.Key.ToString(), de.Value.ToString());
+				base.Add(item);
+			}
+		}
+
 		// Constructor to load from configuration
 		internal EnumList(string name, Configuration cfg)
 		{
 			int index;
 			
-			// Initialize
-			this.name = name;
-
 			// Read the list from configuration
 			IDictionary dic = cfg.ReadSetting("enums." + name, new Hashtable());
 			foreach(DictionaryEntry de in dic)
 			{
-				// Try paring the bit value
-				if(int.TryParse(de.Key.ToString(),
-					NumberStyles.AllowLeadingWhite | NumberStyles.AllowTrailingWhite,
-					CultureInfo.InvariantCulture, out index))
-				{
-					// Add item
-					EnumItem item = new EnumItem(index, de.Value.ToString());
-					base.Add(item);
-				}
-				else
-				{
-					General.WriteLogLine("WARNING: Enum structure '" + name + "' contains invalid keys!");
-				}
+				// Add item
+				EnumItem item = new EnumItem(de.Key.ToString(), de.Value.ToString());
+				base.Add(item);
 			}
 		}
 
@@ -83,14 +80,14 @@ namespace CodeImp.DoomBuilder.Config
 
 		#region ================== Methods
 
-		// This gets an item by enum index
+		// This gets an item by value
 		// Returns null when item could not be found
-		public EnumItem GetByEnumIndex(int enumindex)
+		public EnumItem GetByEnumIndex(string value)
 		{
 			// Find the item
 			foreach(EnumItem i in this)
 			{
-				if(i.Index == enumindex) return i;
+				if(i.Value == value) return i;
 			}
 
 			// Nothing found
diff --git a/Source/Config/LinedefActionInfo.cs b/Source/Config/LinedefActionInfo.cs
index 3a8b6f3f..cd8eb064 100644
--- a/Source/Config/LinedefActionInfo.cs
+++ b/Source/Config/LinedefActionInfo.cs
@@ -46,10 +46,7 @@ namespace CodeImp.DoomBuilder.Config
 		private string category;
 		private string name;
 		private string title;
-		private string[] argtitle;
-		private TagType[] argtagtype;
-		private bool[] argused;
-		private string[] argenum;
+		private ArgumentInfo[] args;
 		
 		#endregion
 
@@ -60,10 +57,7 @@ namespace CodeImp.DoomBuilder.Config
 		public string Category { get { return category; } }
 		public string Name { get { return name; } }
 		public string Title { get { return title; } }
-		public string[] ArgTitle { get { return argtitle; } }
-		public TagType[] ArgTagType { get { return argtagtype; } }
-		public bool[] ArgUsed { get { return argused; } }
-		public string[] ArgEnum { get { return argenum; } }
+		public ArgumentInfo[] Args { get { return args; } }
 
 		#endregion
 
@@ -77,34 +71,17 @@ namespace CodeImp.DoomBuilder.Config
 			// Initialize
 			this.index = index;
 			this.category = categoryname;
-			this.argtitle = new string[Linedef.NUM_ARGS];
-			this.argtagtype = new TagType[Linedef.NUM_ARGS];
-			this.argused = new bool[Linedef.NUM_ARGS];
-			this.argenum = new string[Linedef.NUM_ARGS];
-
+			this.args = new ArgumentInfo[Linedef.NUM_ARGS];
+			
 			// Read settings
 			this.name = cfg.ReadSetting(actionsetting + ".title", "Unnamed");
 			this.prefix = cfg.ReadSetting(actionsetting + ".prefix", "");
 			this.title = this.prefix + " " + this.name;
 			this.title = this.title.Trim();
 
-			// Read the args and marks
+			// Read the args
 			for(int i = 0; i < Linedef.NUM_ARGS; i++)
-			{
-				// Read
-				string istr = i.ToString(CultureInfo.InvariantCulture);
-				this.argused[i] = cfg.SettingExists(actionsetting + ".arg" + istr);
-				this.argtitle[i] = cfg.ReadSetting(actionsetting + ".arg" + istr + ".title", "Argument " + (i + 1));
-				this.argtagtype[i] = (TagType)cfg.ReadSetting(actionsetting + ".arg" + istr + ".tag", (int)TagType.None);
-				this.argenum[i] = cfg.ReadSetting(actionsetting + ".arg" + istr + ".enum", "");
-
-				// Verify enums
-				if((this.argenum[i].Length > 0) && !enums.ContainsKey(this.argenum[i]))
-				{
-					General.WriteLogLine("WARNING: Linedef type enumeration '" + this.argenum[i] + "' does not exist! (found on linedef type " + index + ")");
-					this.argenum[i] = "";
-				}
-			}
+				this.args[i] = new ArgumentInfo(cfg, actionsetting, i, enums);
 			
 			// We have no destructor
 			GC.SuppressFinalize(this);
diff --git a/Source/Controls/ArgumentBox.cs b/Source/Controls/ArgumentBox.cs
index d840926f..08e28955 100644
--- a/Source/Controls/ArgumentBox.cs
+++ b/Source/Controls/ArgumentBox.cs
@@ -70,31 +70,21 @@ namespace CodeImp.DoomBuilder.Controls
 		}
 		
 		// This fills the box with the given enum
-		public void SetupEnums(string enumslistname)
+		public void SetupEnums(EnumList enumslist)
 		{
-			EnumList list;
-
 			// Keep old value
 			int value = this.GetResult(0);
 
 			// Find the enums list
-			if(General.Map.Config.Enums.ContainsKey(enumslistname))
-			{
-				// Enums found
-				list = General.Map.Config.Enums[enumslistname];
+			if(enumslist != null)
 				this.DropDownStyle = ComboBoxStyle.DropDown;
-			}
 			else
-			{
-				// No enums
-				list = null;
 				this.DropDownStyle = ComboBoxStyle.Simple;
-			}
 			
 			// Fill list
-			this.enums = list;
+			this.enums = enumslist;
 			this.Items.Clear();
-			if(list != null) this.Items.AddRange(list.ToArray());
+			if(enumslist != null) this.Items.AddRange(enumslist.ToArray());
 
 			// Re-apply value
 			this.Text = value.ToString();
@@ -115,7 +105,7 @@ namespace CodeImp.DoomBuilder.Controls
 				// Enum selected?
 				if(this.SelectedItem != null)
 				{
-					return (this.SelectedItem as EnumItem).Index;
+					return (this.SelectedItem as EnumItem).GetIntValue();
 				}
 				else
 				{
@@ -174,7 +164,7 @@ namespace CodeImp.DoomBuilder.Controls
 				{
 					// Try selecting this enum
 					EnumItem item = null;
-					if(enums != null) item = enums.GetByEnumIndex(num);
+					if(enums != null) item = enums.GetByEnumIndex(num.ToString());
 					if(item != null)
 					{
 						// Select enum
diff --git a/Source/General/General.cs b/Source/General/General.cs
index ebffd0db..57212ac5 100644
--- a/Source/General/General.cs
+++ b/Source/General/General.cs
@@ -36,6 +36,7 @@ using CodeImp.DoomBuilder.Config;
 using SlimDX.Direct3D9;
 using System.Drawing;
 using CodeImp.DoomBuilder.Plugins;
+using CodeImp.DoomBuilder.Types;
 
 #endregion
 
@@ -109,6 +110,7 @@ namespace CodeImp.DoomBuilder
 		private static ActionManager actions;
 		private static PluginManager plugins;
 		private static ColorCollection colors;
+		private static TypesManager types;
 		private static Clock clock;
 		
 		// Configurations
@@ -145,6 +147,7 @@ namespace CodeImp.DoomBuilder
 		public static Clock Clock { get { return clock; } }
 		public static bool DebugBuild { get { return debugbuild; } }
 		internal static Triangulator EarClipper { get { return earclipper; } }
+		internal static TypesManager Types { get { return types; } }
 		
 		#endregion
 
@@ -524,6 +527,10 @@ namespace CodeImp.DoomBuilder
 				General.WriteLogLine("Creating application clock...");
 				clock = new Clock();
 				
+				// Create types manager
+				General.WriteLogLine("Creating types manager...");
+				types = new TypesManager();
+				
 				// Run application from the main window
 				General.WriteLogLine("Startup done");
 				mainwindow.DisplayReady();
@@ -597,6 +604,7 @@ namespace CodeImp.DoomBuilder
 				if(actions != null) actions.Dispose();
 				if(clock != null) clock.Dispose();
 				if(plugins != null) plugins.Dispose();
+				if(types != null) types.Dispose();
 				try { Direct3D.Terminate(); } catch(Exception) { }
 
 				// Application ends here and now
diff --git a/Source/Types/EnumOptionHandler.cs b/Source/Types/EnumOptionHandler.cs
new file mode 100644
index 00000000..b6075ea7
--- /dev/null
+++ b/Source/Types/EnumOptionHandler.cs
@@ -0,0 +1,143 @@
+
+#region ================== Copyright (c) 2007 Pascal vd Heiden
+
+/*
+ * Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
+ * This program is released under GNU General Public License
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ */
+
+#endregion
+
+#region ================== Namespaces
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+using CodeImp.DoomBuilder.IO;
+using CodeImp.DoomBuilder.Data;
+using System.IO;
+using System.Diagnostics;
+using CodeImp.DoomBuilder.Config;
+
+#endregion
+
+namespace CodeImp.DoomBuilder.Types
+{
+	[TypeHandler(11)]
+	internal class EnumOptionHandler : TypeHandler
+	{
+		#region ================== Constants
+
+		#endregion
+
+		#region ================== Variables
+
+		private EnumList list;
+		private EnumItem value;
+		
+		#endregion
+
+		#region ================== Properties
+
+		public virtual bool IsBrowseable { get { return true; } }
+		public virtual bool IsEnumerable { get { return true; } }
+		
+		#endregion
+
+		#region ================== Constructor
+
+		// When set up for an argument
+		public override void SetupArgument(ArgumentInfo arginfo)
+		{
+			base.SetupArgument(arginfo);
+
+			// Keep enum list reference
+			list = arginfo.Enum;
+		}
+		
+		#endregion
+		
+		#region ================== Methods
+
+		public override void SetValue(object value)
+		{
+			this.value = null;
+			
+			// First try to match the value against the enum values
+			foreach(EnumItem item in list)
+			{
+				// Matching value?
+				if(item.Value == value.ToString())
+				{
+					// Set this value
+					this.value = item;
+				}
+			}
+
+			// No match found yet?
+			if(this.value == null)
+			{
+				// Try to match against the titles
+				foreach(EnumItem item in list)
+				{
+					// Matching value?
+					if(item.Title.ToLowerInvariant() == value.ToString().ToLowerInvariant())
+					{
+						// Set this value
+						this.value = item;
+					}
+				}
+			}
+
+			// Still no match found?
+			if(this.value == null)
+			{
+				// Make a dummy value
+				this.value = new EnumItem(value.ToString(), value.ToString());
+			}
+		}
+
+		public override int GetIntValue()
+		{
+			if(this.value != null)
+			{
+				// Parse the value to integer
+				int result;
+				if(int.TryParse(this.value.Value, NumberStyles.Integer,
+								CultureInfo.InvariantCulture, out result))
+				{
+					return result;
+				}
+				else
+				{
+					return 0;
+				}
+			}
+			else
+			{
+				return 0;
+			}
+		}
+		
+		public override string GetStringValue()
+		{
+			if(this.value != null) return this.value.Title; else return "NULL";
+		}
+
+		// This returns an enum list
+		public override EnumList GetEnumList()
+		{
+			return list;
+		}
+		
+		#endregion
+	}
+}
diff --git a/Source/Types/IntegerHandler.cs b/Source/Types/IntegerHandler.cs
new file mode 100644
index 00000000..e8a836f8
--- /dev/null
+++ b/Source/Types/IntegerHandler.cs
@@ -0,0 +1,90 @@
+
+#region ================== Copyright (c) 2007 Pascal vd Heiden
+
+/*
+ * Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
+ * This program is released under GNU General Public License
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ */
+
+#endregion
+
+#region ================== Namespaces
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+using CodeImp.DoomBuilder.IO;
+using CodeImp.DoomBuilder.Data;
+using System.IO;
+using System.Diagnostics;
+
+#endregion
+
+namespace CodeImp.DoomBuilder.Types
+{
+	[TypeHandler(0)]
+	internal class IntegerHandler : TypeHandler
+	{
+		#region ================== Constants
+
+		#endregion
+
+		#region ================== Variables
+
+		private int value;
+		
+		#endregion
+
+		#region ================== Properties
+
+		public override bool IsCustomType { get { return true; } }
+
+		#endregion
+
+		#region ================== Methods
+
+		public override void SetValue(object value)
+		{
+			int result;
+			
+			// Already an int or float?
+			if((value is int) || (value is float))
+			{
+				// Return the same
+				this.value = (int)value;
+			}
+			else
+			{
+				// Try parsing as string
+				if(int.TryParse(value.ToString(), NumberStyles.Integer, CultureInfo.CurrentCulture, out result))
+				{
+					this.value = result;
+				}
+				else
+				{
+					this.value = 0;
+				}
+			}
+		}
+
+		public override int GetIntValue()
+		{
+			return this.value;
+		}
+
+		public override string GetStringValue()
+		{
+			return this.value.ToString();
+		}
+		
+		#endregion
+	}
+}
diff --git a/Source/Types/NullHandler.cs b/Source/Types/NullHandler.cs
new file mode 100644
index 00000000..5d2805d3
--- /dev/null
+++ b/Source/Types/NullHandler.cs
@@ -0,0 +1,63 @@
+
+#region ================== Copyright (c) 2007 Pascal vd Heiden
+
+/*
+ * Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
+ * This program is released under GNU General Public License
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ */
+
+#endregion
+
+#region ================== Namespaces
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+using CodeImp.DoomBuilder.IO;
+using CodeImp.DoomBuilder.Data;
+using System.IO;
+using System.Diagnostics;
+
+#endregion
+
+namespace CodeImp.DoomBuilder.Types
+{
+	internal class NullHandler : TypeHandler
+	{
+		#region ================== Constants
+
+		#endregion
+
+		#region ================== Variables
+
+		private object value;
+
+		#endregion
+
+		#region ================== Properties
+
+		#endregion
+
+		#region ================== Methods
+
+		public override void SetValue(object value)
+		{
+			this.value = value;
+		}
+
+		public override string GetStringValue()
+		{
+			return this.value.ToString();
+		}
+		
+		#endregion
+	}
+}
diff --git a/Source/Types/TypeHandler.cs b/Source/Types/TypeHandler.cs
new file mode 100644
index 00000000..93069739
--- /dev/null
+++ b/Source/Types/TypeHandler.cs
@@ -0,0 +1,117 @@
+
+#region ================== Copyright (c) 2007 Pascal vd Heiden
+
+/*
+ * Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
+ * This program is released under GNU General Public License
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ */
+
+#endregion
+
+#region ================== Namespaces
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+using CodeImp.DoomBuilder.IO;
+using CodeImp.DoomBuilder.Data;
+using System.IO;
+using System.Diagnostics;
+using System.Windows.Forms;
+using CodeImp.DoomBuilder.Config;
+
+#endregion
+
+namespace CodeImp.DoomBuilder.Types
+{
+	internal abstract class TypeHandler
+	{
+		#region ================== Constants
+
+		#endregion
+
+		#region ================== Variables
+
+		protected int index;
+		protected ArgumentInfo arginfo;
+		
+		#endregion
+
+		#region ================== Properties
+
+		public int Index { get { return index; } }
+
+		public virtual bool IsBrowseable { get { return false; } }
+		public virtual bool IsEnumerable { get { return false; } }
+		public virtual bool IsCustomType { get { return false; } }
+
+		#endregion
+
+		#region ================== Constructor
+
+		// Constructor
+		public TypeHandler()
+		{
+			// Get my attributes
+			object[] attrs = this.GetType().GetCustomAttributes(typeof(TypeHandlerAttribute), false);
+			TypeHandlerAttribute attr = (attrs[0] as TypeHandlerAttribute);
+			
+			// Initialize
+			this.index = attr.Index;
+		}
+
+		// This sets up the handler for arguments
+		public virtual void SetupArgument(ArgumentInfo arginfo)
+		{
+			// Setup
+			this.arginfo = arginfo;
+		}
+		
+		#endregion
+
+		#region ================== Methods
+
+		// This must set the value
+		// How the value is actually validated and stored is up to the implementation
+		public abstract void SetValue(object value);
+
+		// This must return the value as integer (for arguments)
+		public virtual int GetIntValue()
+		{
+			throw new NotSupportedException("Override this method to support it as integer for arguments");
+		}
+
+		// This must return the value as a string for displaying
+		public abstract string GetStringValue();
+
+		// This is called when the user presses the browse button
+		public virtual object Browse(IWin32Window parent)
+		{
+			return null;
+		}
+		
+		// This must returns an enum list when IsEnumerable is true
+		// When the user chooses an enum from this list, it will be
+		// set using SetValue with the EnumItem as value.
+		public virtual EnumList GetEnumList()
+		{
+			return null;
+		}
+		
+		// String representation
+		public override string ToString()
+		{
+			return this.GetStringValue();
+		}
+
+		#endregion
+	}
+}
diff --git a/Source/Types/TypeHandlerAttribute.cs b/Source/Types/TypeHandlerAttribute.cs
new file mode 100644
index 00000000..c5b575eb
--- /dev/null
+++ b/Source/Types/TypeHandlerAttribute.cs
@@ -0,0 +1,66 @@
+
+#region ================== Copyright (c) 2007 Pascal vd Heiden
+
+/*
+ * Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
+ * This program is released under GNU General Public License
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ */
+
+#endregion
+
+#region ================== Namespaces
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+using CodeImp.DoomBuilder.IO;
+using CodeImp.DoomBuilder.Data;
+using System.IO;
+using System.Diagnostics;
+
+#endregion
+
+namespace CodeImp.DoomBuilder.Types
+{
+	internal class TypeHandlerAttribute : Attribute
+	{
+		#region ================== Constants
+
+		#endregion
+
+		#region ================== Variables
+
+		private int index;
+
+		#endregion
+
+		#region ================== Properties
+
+		public int Index { get { return index; } }
+
+		#endregion
+
+		#region ================== Constructor / Destructor
+
+		// Constructor
+		public TypeHandlerAttribute(int index)
+		{
+			// Initialize
+			this.index = index;
+		}
+
+		#endregion
+
+		#region ================== Methods
+
+		#endregion
+	}
+}
diff --git a/Source/Types/TypesManager.cs b/Source/Types/TypesManager.cs
new file mode 100644
index 00000000..12edbad2
--- /dev/null
+++ b/Source/Types/TypesManager.cs
@@ -0,0 +1,120 @@
+
+#region ================== Copyright (c) 2007 Pascal vd Heiden
+
+/*
+ * Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
+ * This program is released under GNU General Public License
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ */
+
+#endregion
+
+#region ================== Namespaces
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+using CodeImp.DoomBuilder.IO;
+using CodeImp.DoomBuilder.Data;
+using System.IO;
+using System.Diagnostics;
+using CodeImp.DoomBuilder.Config;
+
+#endregion
+
+namespace CodeImp.DoomBuilder.Types
+{
+	internal class TypesManager : IDisposable
+	{
+		#region ================== Constants
+
+		#endregion
+
+		#region ================== Variables
+
+		// List of handler types
+		private Dictionary<int, Type> handlertypes;
+		
+		// Disposing
+		private bool isdisposed = false;
+
+		#endregion
+
+		#region ================== Properties
+
+		public bool IsDisposed { get { return isdisposed; } }
+
+		#endregion
+
+		#region ================== Constructor / Disposer
+
+		// Constructor
+		public TypesManager()
+		{
+			// Initialize
+			handlertypes = new Dictionary<int, Type>();
+
+			// Go for all types in this assembly
+			Type[] types = General.ThisAssembly.GetTypes();
+			foreach(Type tp in types)
+			{
+				// Check if this type is a class
+				if(tp.IsClass && !tp.IsAbstract && !tp.IsArray)
+				{
+					// Check if class has an TypeHandler attribute
+					if(Attribute.IsDefined(tp, typeof(TypeHandlerAttribute), false))
+					{
+						// Add the type to the list
+						object[] attribs = tp.GetCustomAttributes(typeof(TypeHandlerAttribute), false);
+						TypeHandlerAttribute attr = (attribs[0] as TypeHandlerAttribute);
+						handlertypes.Add(attr.Index, tp);
+					}
+				}
+			}
+			
+			// We have no destructor
+			GC.SuppressFinalize(this);
+		}
+
+		// Disposer
+		public void Dispose()
+		{
+			// Not already disposed?
+			if(!isdisposed)
+			{
+				// Clean up
+				handlertypes.Clear();
+				
+				// Done
+				isdisposed = true;
+			}
+		}
+
+		#endregion
+
+		#region ================== Methods
+
+		// This returns the type handler for the given argument
+		public TypeHandler GetArgumentHandler(ArgumentInfo arginfo)
+		{
+			Type t = typeof(NullHandler);
+
+			// Do we have a handler type for this?
+			if(handlertypes.ContainsKey(arginfo.Type)) t = handlertypes[arginfo.Type];
+
+			// Create instance
+			TypeHandler th = (TypeHandler)General.ThisAssembly.CreateInstance(t.FullName);
+			th.SetupArgument(arginfo);
+			return th;
+		}
+
+		#endregion
+	}
+}
diff --git a/Source/Windows/LinedefEditForm.Designer.cs b/Source/Windows/LinedefEditForm.Designer.cs
index be9828c3..fb4f670d 100644
--- a/Source/Windows/LinedefEditForm.Designer.cs
+++ b/Source/Windows/LinedefEditForm.Designer.cs
@@ -378,6 +378,7 @@ namespace CodeImp.DoomBuilder.Windows
 			// 
 			// arg4
 			// 
+			this.arg4.DropDownWidth = 200;
 			this.arg4.FormattingEnabled = true;
 			this.arg4.ImeMode = System.Windows.Forms.ImeMode.Off;
 			this.arg4.Location = new System.Drawing.Point(400, 81);
diff --git a/Source/Windows/LinedefEditForm.cs b/Source/Windows/LinedefEditForm.cs
index 10af839b..dc07f14f 100644
--- a/Source/Windows/LinedefEditForm.cs
+++ b/Source/Windows/LinedefEditForm.cs
@@ -352,26 +352,26 @@ namespace CodeImp.DoomBuilder.Windows
 			if(General.Map.Config.LinedefActions.ContainsKey(action.Value)) showaction = action.Value;
 			
 			// Change the argument descriptions
-			arg0label.Text = General.Map.Config.LinedefActions[showaction].ArgTitle[0] + ":";
-			arg1label.Text = General.Map.Config.LinedefActions[showaction].ArgTitle[1] + ":";
-			arg2label.Text = General.Map.Config.LinedefActions[showaction].ArgTitle[2] + ":";
-			arg3label.Text = General.Map.Config.LinedefActions[showaction].ArgTitle[3] + ":";
-			arg4label.Text = General.Map.Config.LinedefActions[showaction].ArgTitle[4] + ":";
-			arg0label.Enabled = General.Map.Config.LinedefActions[showaction].ArgUsed[0];
-			arg1label.Enabled = General.Map.Config.LinedefActions[showaction].ArgUsed[1];
-			arg2label.Enabled = General.Map.Config.LinedefActions[showaction].ArgUsed[2];
-			arg3label.Enabled = General.Map.Config.LinedefActions[showaction].ArgUsed[3];
-			arg4label.Enabled = General.Map.Config.LinedefActions[showaction].ArgUsed[4];
+			arg0label.Text = General.Map.Config.LinedefActions[showaction].Args[0].Title + ":";
+			arg1label.Text = General.Map.Config.LinedefActions[showaction].Args[1].Title + ":";
+			arg2label.Text = General.Map.Config.LinedefActions[showaction].Args[2].Title + ":";
+			arg3label.Text = General.Map.Config.LinedefActions[showaction].Args[3].Title + ":";
+			arg4label.Text = General.Map.Config.LinedefActions[showaction].Args[4].Title + ":";
+			arg0label.Enabled = General.Map.Config.LinedefActions[showaction].Args[0].Used;
+			arg1label.Enabled = General.Map.Config.LinedefActions[showaction].Args[1].Used;
+			arg2label.Enabled = General.Map.Config.LinedefActions[showaction].Args[2].Used;
+			arg3label.Enabled = General.Map.Config.LinedefActions[showaction].Args[3].Used;
+			arg4label.Enabled = General.Map.Config.LinedefActions[showaction].Args[4].Used;
 			if(arg0label.Enabled) arg0.ForeColor = SystemColors.WindowText; else arg0.ForeColor = SystemColors.GrayText;
 			if(arg1label.Enabled) arg1.ForeColor = SystemColors.WindowText; else arg1.ForeColor = SystemColors.GrayText;
 			if(arg2label.Enabled) arg2.ForeColor = SystemColors.WindowText; else arg2.ForeColor = SystemColors.GrayText;
 			if(arg3label.Enabled) arg3.ForeColor = SystemColors.WindowText; else arg3.ForeColor = SystemColors.GrayText;
 			if(arg4label.Enabled) arg4.ForeColor = SystemColors.WindowText; else arg4.ForeColor = SystemColors.GrayText;
-			arg0.SetupEnums(General.Map.Config.LinedefActions[showaction].ArgEnum[0]);
-			arg1.SetupEnums(General.Map.Config.LinedefActions[showaction].ArgEnum[1]);
-			arg2.SetupEnums(General.Map.Config.LinedefActions[showaction].ArgEnum[2]);
-			arg3.SetupEnums(General.Map.Config.LinedefActions[showaction].ArgEnum[3]);
-			arg4.SetupEnums(General.Map.Config.LinedefActions[showaction].ArgEnum[4]);
+			arg0.SetupEnums(General.Map.Config.LinedefActions[showaction].Args[0].Enum);
+			arg1.SetupEnums(General.Map.Config.LinedefActions[showaction].Args[1].Enum);
+			arg2.SetupEnums(General.Map.Config.LinedefActions[showaction].Args[2].Enum);
+			arg3.SetupEnums(General.Map.Config.LinedefActions[showaction].Args[3].Enum);
+			arg4.SetupEnums(General.Map.Config.LinedefActions[showaction].Args[4].Enum);
 		}
 
 		// Browse Action clicked
diff --git a/Source/Windows/ThingEditForm.cs b/Source/Windows/ThingEditForm.cs
index 58243952..0530ff26 100644
--- a/Source/Windows/ThingEditForm.cs
+++ b/Source/Windows/ThingEditForm.cs
@@ -199,26 +199,26 @@ namespace CodeImp.DoomBuilder.Windows
 			if(General.Map.Config.LinedefActions.ContainsKey(action.Value)) showaction = action.Value;
 
 			// Change the argument descriptions
-			arg0label.Text = General.Map.Config.LinedefActions[showaction].ArgTitle[0] + ":";
-			arg1label.Text = General.Map.Config.LinedefActions[showaction].ArgTitle[1] + ":";
-			arg2label.Text = General.Map.Config.LinedefActions[showaction].ArgTitle[2] + ":";
-			arg3label.Text = General.Map.Config.LinedefActions[showaction].ArgTitle[3] + ":";
-			arg4label.Text = General.Map.Config.LinedefActions[showaction].ArgTitle[4] + ":";
-			arg0label.Enabled = General.Map.Config.LinedefActions[showaction].ArgUsed[0];
-			arg1label.Enabled = General.Map.Config.LinedefActions[showaction].ArgUsed[1];
-			arg2label.Enabled = General.Map.Config.LinedefActions[showaction].ArgUsed[2];
-			arg3label.Enabled = General.Map.Config.LinedefActions[showaction].ArgUsed[3];
-			arg4label.Enabled = General.Map.Config.LinedefActions[showaction].ArgUsed[4];
+			arg0label.Text = General.Map.Config.LinedefActions[showaction].Args[0].Title + ":";
+			arg1label.Text = General.Map.Config.LinedefActions[showaction].Args[1].Title + ":";
+			arg2label.Text = General.Map.Config.LinedefActions[showaction].Args[2].Title + ":";
+			arg3label.Text = General.Map.Config.LinedefActions[showaction].Args[3].Title + ":";
+			arg4label.Text = General.Map.Config.LinedefActions[showaction].Args[4].Title + ":";
+			arg0label.Enabled = General.Map.Config.LinedefActions[showaction].Args[0].Used;
+			arg1label.Enabled = General.Map.Config.LinedefActions[showaction].Args[1].Used;
+			arg2label.Enabled = General.Map.Config.LinedefActions[showaction].Args[2].Used;
+			arg3label.Enabled = General.Map.Config.LinedefActions[showaction].Args[3].Used;
+			arg4label.Enabled = General.Map.Config.LinedefActions[showaction].Args[4].Used;
 			if(arg0label.Enabled) arg0.ForeColor = SystemColors.WindowText; else arg0.ForeColor = SystemColors.GrayText;
 			if(arg1label.Enabled) arg1.ForeColor = SystemColors.WindowText; else arg1.ForeColor = SystemColors.GrayText;
 			if(arg2label.Enabled) arg2.ForeColor = SystemColors.WindowText; else arg2.ForeColor = SystemColors.GrayText;
 			if(arg3label.Enabled) arg3.ForeColor = SystemColors.WindowText; else arg3.ForeColor = SystemColors.GrayText;
 			if(arg4label.Enabled) arg4.ForeColor = SystemColors.WindowText; else arg4.ForeColor = SystemColors.GrayText;
-			arg0.SetupEnums(General.Map.Config.LinedefActions[showaction].ArgEnum[0]);
-			arg1.SetupEnums(General.Map.Config.LinedefActions[showaction].ArgEnum[1]);
-			arg2.SetupEnums(General.Map.Config.LinedefActions[showaction].ArgEnum[2]);
-			arg3.SetupEnums(General.Map.Config.LinedefActions[showaction].ArgEnum[3]);
-			arg4.SetupEnums(General.Map.Config.LinedefActions[showaction].ArgEnum[4]);
+			arg0.SetupEnums(General.Map.Config.LinedefActions[showaction].Args[0].Enum);
+			arg1.SetupEnums(General.Map.Config.LinedefActions[showaction].Args[1].Enum);
+			arg2.SetupEnums(General.Map.Config.LinedefActions[showaction].Args[2].Enum);
+			arg3.SetupEnums(General.Map.Config.LinedefActions[showaction].Args[3].Enum);
+			arg4.SetupEnums(General.Map.Config.LinedefActions[showaction].Args[4].Enum);
 		}
 
 		// Browse Action clicked