diff --git a/Documents/udmf10.txt b/Documents/udmf10.txt
new file mode 100644
index 00000000..d9f0ff52
--- /dev/null
+++ b/Documents/udmf10.txt
@@ -0,0 +1,403 @@
+===============================================================================
+Universal Doom Map Format Specification v1.0 - 05/28/08
+
+Written by James "Quasar" Haley - haleyjd@hotmail.com
+
+Defined with input from:
+
+CodeImp
+esselfortium
+Graf Zahl
+Kaiser
+SlayeR
+SoM
+et al.
+
+    Copyright (c) 2008 James Haley.
+    Permission is granted to copy, distribute and/or modify this document
+    under the terms of the GNU Free Documentation License, Version 1.2
+    or any later version published by the Free Software Foundation;
+    with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
+    
+===============================================================================
+
+=======================================
+I. Grammar / Syntax
+=======================================
+
+    translation_unit := global_expr_list
+    global_expr_list := global_expr global_expr_list
+    global_expr := block | assignment_expr
+    block := identifier '{' expr_list '}'
+    expr_list := assignment_expr expr_list
+    assignment_expr := identifier '=' value ';' | nil
+    identifier := [A-Za-z0-9_]+
+    value := integer | float | quoted_string | keyword
+    integer := [+-]?[1-9]+[0-9]* | 0[0-9]+ | 0x[0-9A-Fa-f]+
+    float := [+-]?[0-9]+'.'[0-9]*([eE][+-]?[0-9]+)?
+    quoted_string := "([^"\\]*(\\.[^"\\]*)*)"
+    keyword := [^{}();"'\n\t ]+
+
+
+Global assignments and named/indexed global blocks are the only top-level
+entities supported. Whitespace is strictly ignored.
+
+Comments are supported as C-style single and multi-line comments:
+
+    // single line comment
+    
+    /*
+       multi
+       line
+       comment
+    */
+    
+Multi-line comments may not be nested.
+
+Implementing editors are not required (but are allowed) to maintain syntactic
+comments when rewriting UDMF map lumps. These comments are provided chiefly for
+hand-writing and debugging purposes.
+
+Blocks begin with a keyword identifier. An example of a minimally-defined
+entity follows:
+
+    linedef { id = 1; }
+
+Compliant parsers will ignore all unknown keywords in global assignments, 
+block-level assignments, and block headers. Compliant parsers should attempt
+to preserve as much of such information as is possible by using a flexible
+mapping such as hashing.
+
+Identifiers and keywords are to be treated as case insensitive.
+
+A field which specifies "boolean" semantics shall accept keyword value 
+"true" to mean that the field is asserted, and keyword value "false" to 
+mean that the field is unasserted. Keyword values can only be defined in
+this specification, and not by implementing ports. Use quoted strings
+instead.
+
+Fields which do not appear in a block take on their default value. This
+allows minimal specification. Note that the default values specified by
+UDMF are not necessarily the default values which editors may wish to
+apply to those fields during the creation of new entities during editing.
+Such editing defaults are not part of this specification.
+
+
+=======================================
+II. Implementation Semantics
+=======================================
+
+------------------------------------
+II.A : Storage and Retrieval of Data
+------------------------------------
+
+Block-defined entities are written and read in top-to-bottom order. For
+example, the following linedefs can be assigned in order to a contiguous
+block of memory serving as the implementing port's lines array:
+
+    linedef { id = 1; }
+    linedef { id = 2; }
+    linedef { id = 3; }
+    linedef { id = 4; }
+    
+Data types:
+
+For purposes of internal storage:
+---------------------------------
+Integers should be considered signed with a range of at least 32 bits.
+Floating-point numbers should be considered double precision.
+Strings have no reasonable length limitations.
+
+Hard Data Type Limits
+---------------------
+No limits on number of definitions are defined as part of this specification,
+but implementors may face the need to impose such limitations due to 
+restrictions on the amount of memory available, or the amount that can be
+allocated through a single pointer on the host machine or in a private heap
+implementation.
+
+In the event that a map exceeds such an internal engine limitation, an 
+implementing port or editor should not continue to attempt loading the map, as
+doing so could destabilize the program.
+
+-----------------------------------
+II.B : Storage Within Archive Files
+-----------------------------------
+
+UDMF maps shall be layed out within the archive directory as follows:
+
+    (HEADER)
+    TEXTMAP
+    ... 
+    ENDMAP
+
+(HEADER) = Any lump name from 1 to 8 characters. Serves as the name of the map.
+TEXTMAP  = Single UDMF lump containing all data for the map.
+...      = Blockmap, reject, BSP tree, and port-specific lumps, if any. The
+           format and presence of these resources are not defined by UDMF.
+ENDMAP   = Required closing lump.
+
+Implementing editors and source ports may distinguish a UDMF map from a
+traditional binary map by testing the name of the first directory entry
+following the map header. Implementing resource editors will be capable of
+keeping all lumps for the map, even non-standard ones, together by properly
+scanning for the ENDMAP entry. Non-implementing resource editors will not
+recognize the sequence of lumps as a map, and may thus be less likely to
+interfere with the order or presence of the lumps.
+
+Use of non-implementing resource editors to manipulate UDMF-map-containing WAD
+files is not recommended, however.
+    
+    
+--------------------------------
+II.C : Implementation Dependence
+--------------------------------
+
+A port's list of supported non-standard fields must be provided to implementing
+editors, where they can be provided to the end user as controls, as options
+in a dropbox, or through the ability to input any arbitrary 
+"identifier = value;" pair in a text box.
+
+Every UDMF map should contain as the first statement in the file the "namespace"
+identifier statement, which declares the source port implementation relative to 
+which this map is to be interpreted.
+
+Example:
+
+    namespace = "ZDoom";
+    
+Implementing source ports may ignore this information, or they may use it to 
+perform automatic runtime translation of maps they would otherwise be unable to 
+support.
+
+Implementing source ports should publicly document the value of the "namespace"
+variable they intend to identify with when establishing support for UDMF, and
+avoid conflicts with existing implementations at all costs.
+
+The following namespaces are considered reserved for compatibility purposes:
+
+Doom
+Heretic
+Hexen
+Strife
+
+The use of one of these namespaces indicates that all line specials, sector 
+specials, thing types, and if applicable, thing specials contained in the UDMF 
+map conform to the "vanilla" types for the respective gamemode (with an 
+exception for Doom) and are therefore 100% compatible with all UDMF 
+implementors which support the specified gamemode.
+
+An exception is made for the "Doom" translation type. It is considered to
+represent the final fork of the v1.9 Doom engine, and therefore it includes
+all line types added in DOOM II. It is also additionally considered to 
+include all specials defined in the BOOM and MBF source ports. Implementors
+who support BOOM linedef types can handle these in the normal manner; ports
+which do not support them should zero or otherwise ignore the offending
+specials.
+
+Documentation of the precise meanings of these standardized namespaces will
+be provided in separate documents.
+
+This feature is provided in order to facilitate a universal and lossless
+conversion of all existing Doom-engine-game maps to and from UDMF format,
+independent of any implementing ports' specific namespaces.
+
+
+=======================================
+III. Standardized Fields
+=======================================
+
+The UDMF v1.0 specification considers the following fields standard. They must
+be recognized by all implementing ports and editors (support for the features
+they signify is not necessarily required, such as for ports which do not
+implement Hexen support - all fields unknown to a given port should be 
+ignored and not treated as an error).
+
+   linedef
+   {
+      id = <integer>; // ID of line. Interpreted as tag or scripting id.
+                      // Default = -1. *** see below.
+      
+      v1 = <integer>; // Index of first vertex. No valid default.
+      v2 = <integer>; // Index of second vertex. No valid default.
+      
+      // All flags default to false.
+      
+      blocking      = <bool>; // true = line blocks things.
+      blockmonsters = <bool>; // true = line blocks monsters.
+      twosided      = <bool>; // true = line is 2S.
+      dontpegtop    = <bool>; // true = upper texture unpegged.
+      dontpegbottom = <bool>; // true = lower texture unpegged.
+      secret        = <bool>; // true = drawn as 1S on map.
+      blocksound    = <bool>; // true = blocks sound.
+      dontdraw      = <bool>; // true = line never drawn on map.
+      mapped        = <bool>; // true = always appears on map.
+      
+      // BOOM passuse flag not supported in Strife/Heretic/Hexen namespaces.
+      
+      passuse       = <bool>; // true = passes use action.
+
+      // Strife specific flags. Support for other games is not defined by
+      // default and these flags should be ignored when reading maps not for
+      // the Strife namespace or maps for a port which supports these flags.
+
+      translucent   = <bool>; // true = line is a Strife translucent line.
+      jumpover      = <bool>; // true = line is a Strife railing.
+      blockfloaters = <bool>; // true = line is a Strife float-blocker.
+      
+      // Note: SPAC flags should be set false in Doom/Heretic/Strife
+      // namespace maps. Specials in those games do not support this
+      // mechanism and instead imply activation parameters through the
+      // special number. All flags default to false.
+      
+      playercross   = <bool>; // true = player can cross.
+      playeruse     = <bool>; // true = player can use.
+      monstercross  = <bool>; // true = monster can cross.
+      monsteruse    = <bool>; // true = monster can use.
+      impact        = <bool>; // true = projectile can activate.
+      playerpush    = <bool>; // true = player can push.
+      monsterpush   = <bool>; // true = monster can push.
+      missilecross  = <bool>; // true = projectile can cross.
+      repeatspecial = <bool>; // true = repeatable special.
+      
+      special = <integer>; // Special. Default = 0.
+      arg0    = <integer>; // Argument 0. Default = 0.
+      arg1    = <integer>; // Argument 1. Default = 0.
+      arg2    = <integer>; // Argument 2. Default = 0.
+      arg3    = <integer>; // Argument 3. Default = 0.
+      arg4    = <integer>; // Argument 4. Default = 0.
+      
+      sidefront = <integer>; // Sidedef 1 index. No valid default.
+      sideback  = <integer>; // Sidedef 2 index. Default = -1.
+      
+      comment = <string>; // A comment. Implementors should attach no special
+                          // semantic meaning to this field.
+   }
+   
+   sidedef
+   {
+      offsetx = <integer>; // X Offset. Default = 0.
+      offsety = <integer>; // Y Offset. Default = 0.
+      
+      texturetop    = <string>; // Upper texture. Default = "-".
+      texturebottom = <string>; // Lower texture. Default = "-".
+      texturemiddle = <string>; // Middle texture. Default = "-".
+      
+      sector = <integer>; // Sector index. No valid default.
+
+      comment = <string>; // A comment. Implementors should attach no special
+                          // semantic meaning to this field.
+   }
+   
+   vertex
+   {
+      x = <float>; // X coordinate. No valid default.
+      y = <float>; // Y coordinate. No valid default.
+   }
+   
+   sector
+   {
+      heightfloor   = <integer>; // Floor height. Default = 0.
+      heightceiling = <integer>; // Ceiling height. Default = 0.
+      
+      texturefloor   = <string>; // Floor flat. No valid default.
+      textureceiling = <string>; // Ceiling flat. No valid default.
+      
+      lightlevel = <integer>; // Light level. Default = 160.
+      
+      special = <integer>; // Sector special. Default = 0.
+      id      = <integer>; // Sector tag/id. Default = 0.
+
+      comment = <string>; // A comment. Implementors should attach no special
+                          // semantic meaning to this field.
+   }
+   
+   thing
+   {
+      id = <integer>; // Thing ID. Default = 0.
+      
+      x = <float>; // X coordinate. No valid default.
+      y = <float>; // Y coordinate. No valid default.
+      
+      height = <float>; // Z height relative to floor. Default = 0.
+                        // (Relative to ceiling for SPAWNCEILING items).
+                          
+      angle = <integer>; // Map angle of thing in degrees. Default = 0 (East).
+      
+      type = <integer>; // DoomedNum. No valid default.
+      
+      // All flags default to false.
+      
+      skill1      = <bool>; // true = in skill 1.
+      skill2      = <bool>; // true = in skill 2.
+      skill3      = <bool>; // true = in skill 3.
+      skill4      = <bool>; // true = in skill 4.
+      skill5      = <bool>; // true = in skill 5.
+      ambush      = <bool>; // true = thing is deaf.
+      single      = <bool>; // true = in SP mode.
+      dm          = <bool>; // true = in DM mode.
+      coop        = <bool>; // true = in Coop.
+
+      // MBF friend flag not supported in Strife/Heretic/Hexen namespaces.
+      
+      friend      = <bool>; // true = MBF friend.
+      
+      // Hexen flags; not supported in Doom/Strife/Heretic namespaces.
+      
+      dormant     = <bool>; // true = dormant thing.
+      class1      = <bool>; // true = Present for pclass 1.
+      class2      = <bool>; // true = Present for pclass 2.
+      class3      = <bool>; // true = Present for pclass 3.
+      
+
+      // Strife specific flags. Support for other games is not defined by
+      // default and these flags should be ignored when reading maps not for
+      // the Strife namespace or maps for a port which supports these flags.
+      standing    = <bool>; // true = Strife NPC flag.
+      strifeally  = <bool>; // true = Strife ally flag.
+      translucent = <bool>; // true = Strife translucency flag.
+      invisible   = <bool>; // true = Strife invisibility flag.
+            
+      // Note: suggested editor defaults for all skill, gamemode, and player
+      // class flags is true rather than the UDMF default of false.
+
+      // Thing special semantics are only defined for the Hexen namespace or
+      // ports which implement this feature in their own namespace.
+      
+      special = <integer>; // Scripting special. Default = 0;
+      arg0    = <integer>; // Argument 0. Default = 0.
+      arg1    = <integer>; // Argument 1. Default = 0.
+      arg2    = <integer>; // Argument 2. Default = 0.
+      arg3    = <integer>; // Argument 3. Default = 0.
+      arg4    = <integer>; // Argument 4. Default = 0.
+
+      comment = <string>; // A comment. Implementors should attach no special
+                          // semantic meaning to this field.
+   }
+   
+
+*** Tag / ID Behavior for Map Conversion:
+   
+   Unlike traditional Doom maps UDMF makes a clear distinction between a line's
+   ID and the parameter which identifies the object the line's special is 
+   supposed to affect.
+
+   The id will be used to identify this line, and arg0 will be used to identify
+   the line or sector that this line is to affect or otherwise reference, i.e.
+   it is effectively a parameter to the line's special.
+
+   Boom used the linedef's tag for both due to lack of other options so in 
+   order to ensure compatibility any map converter converting maps for the 
+   Doom/Heretic/Strife namespaces must store the linedef's tag field as both
+   the id and as arg0 in each line. The default value of the id field under 
+   these namespaces is defined as 0 rather than -1.
+   
+   Since UDMF provides a line id field, the Hexen line special #121
+   (Line_SetIdentification) is obsolete. When converting maps to UDMF under
+   Hexen namespace, special 121 should be written as zero, and the arg0 of
+   the binary linedef should be written as the id field of the UDMF line.
+   The arg0 value of the UDMF line should also then be set to zero.
+   
+===============================================================================
+EOF
+===============================================================================
diff --git a/Source/Builder.csproj b/Source/Builder.csproj
index 3925fae4..7964d85d 100644
--- a/Source/Builder.csproj
+++ b/Source/Builder.csproj
@@ -124,6 +124,9 @@
     <Compile Include="Data\DataLocationList.cs" />
     <Compile Include="Data\DataManager.cs" />
     <Compile Include="Data\WADReader.cs" />
+    <Compile Include="Map\MapElement.cs" />
+    <Compile Include="Map\UniFields.cs" />
+    <Compile Include="Map\UniValue.cs" />
     <Compile Include="Types\BoolHandler.cs" />
     <Compile Include="Types\ColorHandler.cs" />
     <Compile Include="Types\EnumBitsHandler.cs" />
diff --git a/Source/Editing/ThingsFilter.cs b/Source/Editing/ThingsFilter.cs
index b9e21d6d..a51e8b31 100644
--- a/Source/Editing/ThingsFilter.cs
+++ b/Source/Editing/ThingsFilter.cs
@@ -211,7 +211,7 @@ namespace CodeImp.DoomBuilder.Editing
 						{
 							if(t.Fields[s] is bool)
 							{
-								if((bool)t.Fields[s] == false)
+								if((bool)t.Fields[s].Value == false)
 								{
 									qualifies = false;
 									break;
@@ -236,7 +236,7 @@ namespace CodeImp.DoomBuilder.Editing
 						{
 							if(t.Fields[s] is bool)
 							{
-								if((bool)t.Fields[s] == true)
+								if((bool)t.Fields[s].Value == true)
 								{
 									qualifies = false;
 									break;
diff --git a/Source/Map/Linedef.cs b/Source/Map/Linedef.cs
index 384b080c..5f545ebd 100644
--- a/Source/Map/Linedef.cs
+++ b/Source/Map/Linedef.cs
@@ -30,7 +30,7 @@ using System.Drawing;
 
 namespace CodeImp.DoomBuilder.Map
 {
-	public sealed class Linedef
+	public sealed class Linedef : MapElement
 	{
 		#region ================== Constants
 
@@ -73,15 +73,9 @@ namespace CodeImp.DoomBuilder.Map
 		private int tag;
 		private int[] args;
 		
-		// Additional fields
-		private SortedList<string, object> fields;
-		
 		// Selections
 		private bool selected;
 		private bool marked;
-		
-		// Disposing
-		private bool isdisposed = false;
 
 		#endregion
 
@@ -92,7 +86,6 @@ namespace CodeImp.DoomBuilder.Map
 		public Vertex End { get { return end; } }
 		public Sidedef Front { get { return front; } }
 		public Sidedef Back { get { return back; } }
-		public bool IsDisposed { get { return isdisposed; } }
 		public Line2D Line { get { return new Line2D(start.Position, end.Position); } }
 		public int Flags { get { return flags; } set { flags = value; } }
 		public int Action { get { return action; } set { action = value; } }
@@ -106,7 +99,6 @@ namespace CodeImp.DoomBuilder.Map
 		public int AngleDeg { get { return (int)(angle * Angle2D.PIDEG); } }
 		public RectangleF Rect { get { return rect; } }
 		public int[] Args { get { return args; } }
-		public SortedList<string, object> Fields { get { return fields; } }
 
 		#endregion
 
@@ -132,7 +124,7 @@ namespace CodeImp.DoomBuilder.Map
 		}
 
 		// Disposer
-		public void Dispose()
+		public override void Dispose()
 		{
 			// Not already disposed?
 			if(!isdisposed)
@@ -160,6 +152,9 @@ namespace CodeImp.DoomBuilder.Map
 				front = null;
 				back = null;
 				map = null;
+
+				// Clean up base
+				base.Dispose();
 			}
 		}
 
@@ -198,8 +193,8 @@ namespace CodeImp.DoomBuilder.Map
 			l.flags = flags;
 			l.tag = tag;
 			l.updateneeded = true;
-			if(fields != null) l.MakeFields(fields);
 			l.selected = selected;
+			CopyFieldsTo(l);
 		}
 		
 		// This attaches a sidedef on the front
@@ -288,23 +283,6 @@ namespace CodeImp.DoomBuilder.Map
 			if(back != null) back.Sector.UpdateNeeded = true;
 		}
 
-		#endregion
-
-		#region ================== Fields
-
-		// This makes new fields
-		public void MakeFields()
-		{
-			if(fields != null) fields = new SortedList<string, object>();
-		}
-
-		// This makes fields from another list of fields
-		public void MakeFields(SortedList<string, object> copyfrom)
-		{
-			if(fields != null) fields = new SortedList<string, object>();
-			foreach(KeyValuePair<string, object> f in copyfrom) fields[f.Key] = f.Value;
-		}
-
 		#endregion
 		
 		#region ================== Methods
diff --git a/Source/Map/MapElement.cs b/Source/Map/MapElement.cs
new file mode 100644
index 00000000..9279898c
--- /dev/null
+++ b/Source/Map/MapElement.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.Geometry;
+using CodeImp.DoomBuilder.Rendering;
+using SlimDX.Direct3D9;
+using System.Drawing;
+
+#endregion
+
+namespace CodeImp.DoomBuilder.Map
+{
+	public abstract class MapElement : IDisposable
+	{
+		#region ================== Constants
+
+		#endregion
+
+		#region ================== Variables
+
+		// Univeral fields
+		private UniFields fields;
+
+		// Disposing
+		protected bool isdisposed = false;
+		
+		#endregion
+
+		#region ================== Properties
+
+		public UniFields Fields { get { return fields; } }
+		public bool IsDisposed { get { return isdisposed; } }
+		
+		#endregion
+
+		#region ================== Constructor / Disposer
+
+		// Constructor
+		internal MapElement()
+		{
+			// Initialize
+			fields = new UniFields();
+		}
+
+		// Disposer
+		public virtual void Dispose()
+		{
+			if(!isdisposed)
+			{
+				// Clean up
+				fields = null;
+				
+				// Done
+				isdisposed = true;
+			}
+		}
+
+		#endregion
+
+		#region ================== Fields
+		
+		// This copies fields to any other element
+		protected void CopyFieldsTo(MapElement element)
+		{
+			element.fields = new UniFields(this.fields);
+		}
+		
+		#endregion
+	}
+}
diff --git a/Source/Map/Sector.cs b/Source/Map/Sector.cs
index 9d721a13..12237692 100644
--- a/Source/Map/Sector.cs
+++ b/Source/Map/Sector.cs
@@ -30,7 +30,7 @@ using CodeImp.DoomBuilder.Rendering;
 
 namespace CodeImp.DoomBuilder.Map
 {
-	public sealed class Sector
+	public sealed class Sector : MapElement
 	{
 		#region ================== Constants
 
@@ -75,12 +75,6 @@ namespace CodeImp.DoomBuilder.Map
 		private TriangleList triverts;
 		private FlatVertex[] vertices;
 
-		// Additional fields
-		private SortedList<string, object> fields;
-		
-		// Disposing
-		private bool isdisposed = false;
-
 		#endregion
 
 		#region ================== Properties
@@ -88,7 +82,6 @@ namespace CodeImp.DoomBuilder.Map
 		public MapSet Map { get { return map; } }
 		public ICollection<Sidedef> Sidedefs { get { return sidedefs; } }
 		public ICollection<Thing> Things { get { return things; } }
-		public bool IsDisposed { get { return isdisposed; } }
 		public int Index { get { return index; } }
 		public int FloorHeight { get { return floorheight; } set { floorheight = value; } }
 		public int CeilHeight { get { return ceilheight; } set { ceilheight = value; } }
@@ -104,7 +97,6 @@ namespace CodeImp.DoomBuilder.Map
 		public bool UpdateNeeded { get { return updateneeded; } set { updateneeded |= value; triangulationneeded |= value; } }
 		public Sector Clone { get { return clone; } set { clone = value; } }
 		public FlatVertex[] Vertices { get { return vertices; } }
-		public SortedList<string, object> Fields { get { return fields; } }
 
 		#endregion
 
@@ -129,7 +121,7 @@ namespace CodeImp.DoomBuilder.Map
 		}
 
 		// Disposer
-		public void Dispose()
+		public override void Dispose()
 		{
 			// Not already disposed?
 			if(!isdisposed)
@@ -152,6 +144,9 @@ namespace CodeImp.DoomBuilder.Map
 				sidedefs = null;
 				things = null;
 				map = null;
+
+				// Dispose base
+				base.Dispose();
 			}
 		}
 
@@ -172,9 +167,9 @@ namespace CodeImp.DoomBuilder.Map
 			s.effect = effect;
 			s.tag = tag;
 			s.brightness = brightness;
-			if(fields != null) s.MakeFields(fields);
 			s.selected = selected;
 			s.updateneeded = true;
+			CopyFieldsTo(s);
 		}
 		
 		// This attaches a sidedef and returns the listitem
@@ -250,23 +245,6 @@ namespace CodeImp.DoomBuilder.Map
 		
 		#endregion
 
-		#region ================== Fields
-
-		// This makes new fields
-		public void MakeFields()
-		{
-			if(fields != null) fields = new SortedList<string, object>();
-		}
-
-		// This makes fields from another list of fields
-		public void MakeFields(SortedList<string, object> copyfrom)
-		{
-			if(fields != null) fields = new SortedList<string, object>();
-			foreach(KeyValuePair<string, object> f in copyfrom) fields[f.Key] = f.Value;
-		}
-
-		#endregion
-
 		#region ================== Methods
 
 		// This joins the sector with another sector
diff --git a/Source/Map/Sidedef.cs b/Source/Map/Sidedef.cs
index 27ffbe3a..2b1cf773 100644
--- a/Source/Map/Sidedef.cs
+++ b/Source/Map/Sidedef.cs
@@ -28,7 +28,7 @@ using CodeImp.DoomBuilder.Geometry;
 
 namespace CodeImp.DoomBuilder.Map
 {
-	public sealed class Sidedef
+	public sealed class Sidedef : MapElement
 	{
 		#region ================== Constants
 
@@ -59,14 +59,8 @@ namespace CodeImp.DoomBuilder.Map
 		private long longtexnamemid;
 		private long longtexnamelow;
 
-		// Additional fields
-		private SortedList<string, object> fields;
-
 		// Selections
 		private bool marked;
-		
-		// Disposing
-		private bool isdisposed = false;
 
 		#endregion
 
@@ -77,7 +71,6 @@ namespace CodeImp.DoomBuilder.Map
 		public Linedef Line { get { return linedef; } }
 		public Sidedef Other { get { if(this == linedef.Front) return linedef.Back; else return linedef.Front; } }
 		public Sector Sector { get { return sector; } }
-		public bool IsDisposed { get { return isdisposed; } }
 		public float Angle { get { if(IsFront) return linedef.Angle; else return Angle2D.Normalized(linedef.Angle + Angle2D.PI); } }
 		public int OffsetX { get { return offsetx; } set { offsetx = value; } }
 		public int OffsetY { get { return offsety; } set { offsety = value; } }
@@ -88,7 +81,6 @@ namespace CodeImp.DoomBuilder.Map
 		public long LongMiddleTexture { get { return longtexnamemid; } }
 		public long LongLowTexture { get { return longtexnamelow; } }
 		public bool Marked { get { return marked; } set { marked = value; } }
-		public SortedList<string, object> Fields { get { return fields; } }
 		
 		#endregion
 
@@ -120,7 +112,7 @@ namespace CodeImp.DoomBuilder.Map
 		}
 
 		// Disposer
-		public void Dispose()
+		public override void Dispose()
 		{
 			// Not already disposed?
 			if(!isdisposed)
@@ -143,6 +135,9 @@ namespace CodeImp.DoomBuilder.Map
 				linedef = null;
 				map = null;
 				sector = null;
+
+				// Dispose base
+				base.Dispose();
 			}
 		}
 
@@ -162,7 +157,7 @@ namespace CodeImp.DoomBuilder.Map
 			s.longtexnamehigh = longtexnamehigh;
 			s.longtexnamemid = longtexnamemid;
 			s.longtexnamelow = longtexnamelow;
-			if(fields != null) s.MakeFields(fields);
+			CopyFieldsTo(s);
 		}
 		
 		// This copies textures to another sidedef
@@ -216,23 +211,6 @@ namespace CodeImp.DoomBuilder.Map
 			}
 		}
 		
-		#endregion
-		
-		#region ================== Fields
-
-		// This makes new fields
-		public void MakeFields()
-		{
-			if(fields != null) fields = new SortedList<string, object>();
-		}
-
-		// This makes fields from another list of fields
-		public void MakeFields(SortedList<string, object> copyfrom)
-		{
-			if(fields != null) fields = new SortedList<string, object>();
-			foreach(KeyValuePair<string, object> f in copyfrom) fields[f.Key] = f.Value;
-		}
-		
 		#endregion
 
 		#region ================== Methods
diff --git a/Source/Map/Thing.cs b/Source/Map/Thing.cs
index 7ef289ff..b54cf91a 100644
--- a/Source/Map/Thing.cs
+++ b/Source/Map/Thing.cs
@@ -30,7 +30,7 @@ using System.Drawing;
 
 namespace CodeImp.DoomBuilder.Map
 {
-	public sealed class Thing
+	public sealed class Thing : MapElement
 	{
 		#region ================== Constants
 
@@ -70,12 +70,6 @@ namespace CodeImp.DoomBuilder.Map
 		private bool selected;
 		private bool marked;
 
-		// Additional fields
-		private SortedList<string, object> fields;
-		
-		// Disposing
-		private bool isdisposed = false;
-
 		#endregion
 
 		#region ================== Properties
@@ -83,7 +77,6 @@ namespace CodeImp.DoomBuilder.Map
 		public MapSet Map { get { return map; } }
 		public int Type { get { return type; } set { type = value; } }
 		public Vector3D Position { get { return pos; } }
-		public bool IsDisposed { get { return isdisposed; } }
 		public float Angle { get { return angle; } }
 		public int AngleDeg { get { return (int)Angle2D.RadToDeg(angle); } }
 		public int Flags { get { return flags; } set { flags = value; } }
@@ -99,7 +92,6 @@ namespace CodeImp.DoomBuilder.Map
 		public int ZOffset { get { return zoffset; } set { zoffset = value; } }
 		public int Tag { get { return tag; } set { tag = value; if((tag < 0) || (tag > MapSet.HIGHEST_TAG)) throw new ArgumentOutOfRangeException("Tag", "Invalid tag number"); } }
 		public Sector Sector { get { return sector; } }
-		public SortedList<string, object> Fields { get { return fields; } }
 
 		#endregion
 
@@ -117,7 +109,7 @@ namespace CodeImp.DoomBuilder.Map
 		}
 
 		// Disposer
-		public void Dispose()
+		public override void Dispose()
 		{
 			// Not already disposed?
 			if(!isdisposed)
@@ -136,6 +128,9 @@ namespace CodeImp.DoomBuilder.Map
 				sectorlistitem = null;
 				map = null;
 				sector = null;
+
+				// Dispose base
+				base.Dispose();
 			}
 		}
 
@@ -161,8 +156,8 @@ namespace CodeImp.DoomBuilder.Map
 			t.color = color;
 			t.iconoffset = iconoffset;
 			args.CopyTo(t.args, 0);
-			if(fields != null) t.MakeFields(fields);
 			t.selected = selected;
+			CopyFieldsTo(t);
 		}
 		
 		// This determines which sector the thing is in and links it
@@ -206,23 +201,6 @@ namespace CodeImp.DoomBuilder.Map
 			}
 		}
 		
-		#endregion
-
-		#region ================== Fields
-
-		// This makes new fields
-		public void MakeFields()
-		{
-			if(fields != null) fields = new SortedList<string, object>();
-		}
-
-		// This makes fields from another list of fields
-		public void MakeFields(SortedList<string, object> copyfrom)
-		{
-			if(fields != null) fields = new SortedList<string, object>();
-			foreach(KeyValuePair<string, object> f in copyfrom) fields[f.Key] = f.Value;
-		}
-
 		#endregion
 		
 		#region ================== Changes
diff --git a/Source/Map/UniFields.cs b/Source/Map/UniFields.cs
new file mode 100644
index 00000000..b81c4669
--- /dev/null
+++ b/Source/Map/UniFields.cs
@@ -0,0 +1,25 @@
+#region ================== Namespaces
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+
+#endregion
+
+namespace CodeImp.DoomBuilder.Map
+{
+	public class UniFields : SortedList<string, UniValue>
+	{
+		// New constructor
+		public UniFields() : base(2)
+		{
+		}
+		
+		// Copy constructor
+		public UniFields(UniFields copyfrom) : base(copyfrom)
+		{
+		}
+	}
+}
diff --git a/Source/Map/UniValue.cs b/Source/Map/UniValue.cs
new file mode 100644
index 00000000..7791dd8a
--- /dev/null
+++ b/Source/Map/UniValue.cs
@@ -0,0 +1,85 @@
+
+#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.Geometry;
+using CodeImp.DoomBuilder.Rendering;
+using SlimDX.Direct3D9;
+using System.Drawing;
+using CodeImp.DoomBuilder.Types;
+
+#endregion
+
+namespace CodeImp.DoomBuilder.Map
+{
+	public class UniValue
+	{
+		#region ================== Constants
+
+		#endregion
+
+		#region ================== Variables
+		
+		private object value;
+		private int type;
+
+		#endregion
+
+		#region ================== Properties
+
+		public object Value
+		{
+			get
+			{
+				return this.value;
+			}
+			
+			set
+			{
+				// Value may only be a primitive type
+				if(!(value is int) || !(value is float) || !(value is string) || !(value is bool))
+					throw new ArgumentException("Universal field values can only be of type int, float, string or bool.");
+				
+				this.value = value;
+			}
+		}
+		
+		public int Type { get { return this.type; } set { this.type = value; } }
+
+		#endregion
+
+		#region ================== Constructor
+
+		// Constructor
+		public UniValue()
+		{
+			// We have no destructor
+			GC.SuppressFinalize(this);
+		}
+		
+		#endregion
+
+		#region ================== Methods
+
+		#endregion
+	}
+}
diff --git a/Source/Map/Vertex.cs b/Source/Map/Vertex.cs
index bf9bcc9d..6d9f8b21 100644
--- a/Source/Map/Vertex.cs
+++ b/Source/Map/Vertex.cs
@@ -30,7 +30,7 @@ using System.Drawing;
 
 namespace CodeImp.DoomBuilder.Map
 {
-	public sealed class Vertex
+	public sealed class Vertex : MapElement
 	{
 		#region ================== Constants
 		
@@ -60,12 +60,6 @@ namespace CodeImp.DoomBuilder.Map
 		// Cloning
 		private Vertex clone;
 
-		// Additional fields
-		private SortedList<string, object> fields;
-		
-		// Disposing
-		private bool isdisposed = false;
-
 		#endregion
 
 		#region ================== Properties
@@ -73,11 +67,9 @@ namespace CodeImp.DoomBuilder.Map
 		public MapSet Map { get { return map; } }
 		public ICollection<Linedef> Linedefs { get { return linedefs; } }
 		public Vector2D Position { get { return pos; } }
-		public bool IsDisposed { get { return isdisposed; } }
 		public bool Selected { get { return selected; } set { selected = value; } }
 		public bool Marked { get { return marked; } set { marked = value; } }
 		public Vertex Clone { get { return clone; } set { clone = value; } }
-		public SortedList<string, object> Fields { get { return fields; } }
 
 		#endregion
 
@@ -97,7 +89,7 @@ namespace CodeImp.DoomBuilder.Map
 		}
 
 		// Disposer
-		public void Dispose()
+		public override void Dispose()
 		{
 			// Not already disposed?
 			if(!isdisposed)
@@ -116,6 +108,9 @@ namespace CodeImp.DoomBuilder.Map
 				linedefs = null;
 				mainlistitem = null;
 				map = null;
+
+				// Dispose base
+				base.Dispose();
 			}
 		}
 
@@ -144,23 +139,6 @@ namespace CodeImp.DoomBuilder.Map
 			}
 		}
 
-		#endregion
-
-		#region ================== Fields
-
-		// This makes new fields
-		public void MakeFields()
-		{
-			if(fields != null) fields = new SortedList<string, object>();
-		}
-
-		// This makes fields from another list of fields
-		public void MakeFields(SortedList<string, object> copyfrom)
-		{
-			if(fields != null) fields = new SortedList<string, object>();
-			foreach(KeyValuePair<string, object> f in copyfrom) fields[f.Key] = f.Value;
-		}
-
 		#endregion
 		
 		#region ================== Methods
@@ -170,8 +148,8 @@ namespace CodeImp.DoomBuilder.Map
 		{
 			// Copy properties
 			v.pos = pos;
-			if(fields != null) v.MakeFields(fields);
 			v.selected = selected;
+			CopyFieldsTo(v);
 		}
 		
 		// This returns the distance from given coordinates