diff --git a/SabreTools.Library/DatFiles/Json.cs b/SabreTools.Library/DatFiles/Json.cs
index 3af90a1b..1b06e0ce 100644
--- a/SabreTools.Library/DatFiles/Json.cs
+++ b/SabreTools.Library/DatFiles/Json.cs
@@ -250,6 +250,9 @@ namespace SabreTools.Library.DatFiles
                     case ItemType.Feature:
                         datItem = datItemObj.ToObject<Feature>();
                         break;
+                    case ItemType.Instance:
+                        datItem = datItemObj.ToObject<Instance>();
+                        break;
                     case ItemType.Media:
                         datItem = datItemObj.ToObject<Media>();
                         break;
diff --git a/SabreTools.Library/DatItems/Analog.cs b/SabreTools.Library/DatItems/Analog.cs
index 04338144..9e019f84 100644
--- a/SabreTools.Library/DatItems/Analog.cs
+++ b/SabreTools.Library/DatItems/Analog.cs
@@ -34,8 +34,8 @@ namespace SabreTools.Library.DatItems
             base.SetFields(mappings);
 
             // Handle Analog-specific fields
-            if (mappings.Keys.Contains(Field.DatItem_Mask))
-                Mask = mappings[Field.DatItem_Mask];
+            if (mappings.Keys.Contains(Field.Machine_Port_Analog_Mask))
+                Mask = mappings[Field.Machine_Port_Analog_Mask];
         }
 
         #endregion
@@ -138,7 +138,7 @@ namespace SabreTools.Library.DatItems
             base.RemoveFields(fields);
 
             // Remove the fields
-            if (fields.Contains(Field.DatItem_Mask))
+            if (fields.Contains(Field.Machine_Port_Analog_Mask))
                 Mask = null;
         }
 
@@ -164,7 +164,7 @@ namespace SabreTools.Library.DatItems
             Analog newItem = item as Analog;
 
             // Replace the fields
-            if (fields.Contains(Field.DatItem_Mask))
+            if (fields.Contains(Field.Machine_Port_Analog_Mask))
                 Mask = newItem.Mask;
         }
 
diff --git a/SabreTools.Library/DatItems/Auxiliary.cs b/SabreTools.Library/DatItems/Auxiliary.cs
index 6691fff2..6cb19455 100644
--- a/SabreTools.Library/DatItems/Auxiliary.cs
+++ b/SabreTools.Library/DatItems/Auxiliary.cs
@@ -290,29 +290,6 @@ namespace SabreTools.Library.DatItems
         #endregion
     }
 
-    /// <summary>
-    /// Represents one ListXML instance
-    /// </summary>
-    [JsonObject("instance")]
-    public class Instance
-    {
-        #region Fields
-
-        /// <summary>
-        /// Name of the instance
-        /// </summary>
-        [JsonProperty("name")]
-        public string Name { get; set; }
-
-        /// <summary>
-        /// Short name for the instance
-        /// </summary>
-        [JsonProperty("briefname", DefaultValueHandling = DefaultValueHandling.Ignore)]
-        public string BriefName { get; set; }
-
-        #endregion
-    }
-
     /// <summary>
     /// Represents one ListXML conflocation or diplocation
     /// </summary>
diff --git a/SabreTools.Library/DatItems/DatItem.cs b/SabreTools.Library/DatItems/DatItem.cs
index 9672634d..5b32b6c2 100644
--- a/SabreTools.Library/DatItems/DatItem.cs
+++ b/SabreTools.Library/DatItems/DatItem.cs
@@ -497,6 +497,9 @@ namespace SabreTools.Library.DatItems
                 case ItemType.Feature:
                     return new Feature();
 
+                case ItemType.Instance:
+                    return new Instance();
+
                 case ItemType.Media:
                     return new Media();
 
@@ -541,6 +544,7 @@ namespace SabreTools.Library.DatItems
                 ItemType.Driver => new Driver(),
                 ItemType.Extension => new Extension(),
                 ItemType.Feature => new Feature(),
+                ItemType.Instance => new Instance(),
                 ItemType.Media => new Media(),
                 ItemType.RamOption => new RamOption(),
                 ItemType.Release => new Release(),
diff --git a/SabreTools.Library/DatItems/Enums.cs b/SabreTools.Library/DatItems/Enums.cs
index 0adf055d..0b77fae0 100644
--- a/SabreTools.Library/DatItems/Enums.cs
+++ b/SabreTools.Library/DatItems/Enums.cs
@@ -497,6 +497,7 @@ namespace SabreTools.Library.DatItems
         Driver,
         Extension,
         Feature,
+        Instance,
         RamOption,
         Release,
         Sample,
diff --git a/SabreTools.Library/DatItems/Extension.cs b/SabreTools.Library/DatItems/Extension.cs
index a31fe0ec..499041d4 100644
--- a/SabreTools.Library/DatItems/Extension.cs
+++ b/SabreTools.Library/DatItems/Extension.cs
@@ -45,8 +45,8 @@ namespace SabreTools.Library.DatItems
             base.SetFields(mappings);
 
             // Handle Sample-specific fields
-            if (mappings.Keys.Contains(Field.DatItem_Name))
-                Name = mappings[Field.DatItem_Name];
+            if (mappings.Keys.Contains(Field.Machine_Device_Extension_Name))
+                Name = mappings[Field.Machine_Device_Extension_Name];
         }
 
         #endregion
@@ -158,9 +158,9 @@ namespace SabreTools.Library.DatItems
                 return false;
 
             // Filter on item name
-            if (filter.DatItem_Name.MatchesPositiveSet(Name) == false)
+            if (filter.Machine_Device_Extension_Name.MatchesPositiveSet(Name) == false)
                 return false;
-            if (filter.DatItem_Name.MatchesNegativeSet(Name) == true)
+            if (filter.Machine_Device_Extension_Name.MatchesNegativeSet(Name) == true)
                 return false;
 
             return true;
@@ -176,7 +176,7 @@ namespace SabreTools.Library.DatItems
             base.RemoveFields(fields);
 
             // Remove the fields
-            if (fields.Contains(Field.DatItem_Name))
+            if (fields.Contains(Field.Machine_Device_Extension_Name))
                 Name = null;
         }
 
@@ -212,7 +212,7 @@ namespace SabreTools.Library.DatItems
             Extension newItem = item as Extension;
 
             // Replace the fields
-            if (fields.Contains(Field.DatItem_Name))
+            if (fields.Contains(Field.Machine_Device_Extension_Name))
                 Name = newItem.Name;
         }
 
diff --git a/SabreTools.Library/DatItems/Instance.cs b/SabreTools.Library/DatItems/Instance.cs
new file mode 100644
index 00000000..35bc8423
--- /dev/null
+++ b/SabreTools.Library/DatItems/Instance.cs
@@ -0,0 +1,244 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+using SabreTools.Library.Filtering;
+using SabreTools.Library.Tools;
+using Newtonsoft.Json;
+
+namespace SabreTools.Library.DatItems
+{
+    /// <summary>
+    /// Represents a single instance of another item
+    /// </summary>
+    [JsonObject("instance")]
+    public class Instance : DatItem
+    {
+        #region Fields
+
+        /// <summary>
+        /// Name of the item
+        /// </summary>
+        [JsonProperty("name")]
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Short name for the instance
+        /// </summary>
+        [JsonProperty("briefname", DefaultValueHandling = DefaultValueHandling.Ignore)]
+        public string BriefName { get; set; }
+
+        #endregion
+
+        #region Accessors
+
+        /// <summary>
+        /// Gets the name to use for a DatItem
+        /// </summary>
+        /// <returns>Name if available, null otherwise</returns>
+        public override string GetName()
+        {
+            return Name;
+        }
+
+        /// <summary>
+        /// Set fields with given values
+        /// </summary>
+        /// <param name="mappings">Mappings dictionary</param>
+        public override void SetFields(Dictionary<Field, string> mappings)
+        {
+            // Set base fields
+            base.SetFields(mappings);
+
+            // Handle Instance-specific fields
+            if (mappings.Keys.Contains(Field.Machine_Device_Instance_Name))
+                Name = mappings[Field.Machine_Device_Instance_Name];
+
+            if (mappings.Keys.Contains(Field.Machine_Device_Instance_BriefName))
+                BriefName = mappings[Field.Machine_Device_Instance_BriefName];
+        }
+
+        #endregion
+
+        #region Constructors
+
+        /// <summary>
+        /// Create a default, empty Instance object
+        /// </summary>
+        public Instance()
+        {
+            Name = string.Empty;
+            ItemType = ItemType.Instance;
+        }
+
+        #endregion
+
+        #region Cloning Methods
+
+        public override object Clone()
+        {
+            return new Instance()
+            {
+                Name = this.Name,
+                ItemType = this.ItemType,
+                DupeType = this.DupeType,
+
+                AltName = this.AltName,
+                AltTitle = this.AltTitle,
+
+                Original = this.Original,
+                OpenMSXSubType = this.OpenMSXSubType,
+                OpenMSXType = this.OpenMSXType,
+                Remark = this.Remark,
+                Boot = this.Boot,
+
+                Part = this.Part,
+                Features = this.Features,
+                AreaName = this.AreaName,
+                AreaSize = this.AreaSize,
+                AreaWidth = this.AreaWidth,
+                AreaEndianness = this.AreaEndianness,
+                Value = this.Value,
+                LoadFlag = this.LoadFlag,
+
+                Machine = this.Machine.Clone() as Machine,
+                Source = this.Source.Clone() as Source,
+                Remove = this.Remove,
+
+                BriefName = this.BriefName,
+            };
+        }
+
+        #endregion
+
+        #region Comparision Methods
+
+        public override bool Equals(DatItem other)
+        {
+            // If we don't have a Instance, return false
+            if (ItemType != other.ItemType)
+                return false;
+
+            // Otherwise, treat it as a Instance
+            Instance newOther = other as Instance;
+
+            // If the Instance information matches
+            return (Name == newOther.Name && BriefName == newOther.BriefName);
+        }
+
+        #endregion
+
+        #region Filtering
+
+        /// <summary>
+        /// Clean a DatItem according to the cleaner
+        /// </summary>
+        /// <param name="cleaner">Cleaner to implement</param>
+        public override void Clean(Cleaner cleaner)
+        {
+            // Clean common items first
+            base.Clean(cleaner);
+
+            // If we're stripping unicode characters, strip item name
+            if (cleaner?.RemoveUnicode == true)
+                Name = Sanitizer.RemoveUnicodeCharacters(Name);
+
+            // If we are in NTFS trim mode, trim the game name
+            if (cleaner?.Trim == true)
+            {
+                // Windows max name length is 260
+                int usableLength = 260 - Machine.Name.Length - (cleaner.Root?.Length ?? 0);
+                if (Name.Length > usableLength)
+                {
+                    string ext = Path.GetExtension(Name);
+                    Name = Name.Substring(0, usableLength - ext.Length);
+                    Name += ext;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Check to see if a DatItem passes the filter
+        /// </summary>
+        /// <param name="filter">Filter to check against</param>
+        /// <returns>True if the item passed the filter, false otherwise</returns>
+        public override bool PassesFilter(Filter filter)
+        {
+            // Check common fields first
+            if (!base.PassesFilter(filter))
+                return false;
+
+            // Filter on item name
+            if (filter.Machine_Device_Instance_Name.MatchesPositiveSet(Name) == false)
+                return false;
+            if (filter.Machine_Device_Instance_Name.MatchesNegativeSet(Name) == true)
+                return false;
+
+            // Filter on brief name
+            if (filter.Machine_Device_Instance_BriefName.MatchesPositiveSet(Name) == false)
+                return false;
+            if (filter.Machine_Device_Instance_BriefName.MatchesNegativeSet(Name) == true)
+                return false;
+
+            return true;
+        }
+
+        /// <summary>
+        /// Remove fields from the DatItem
+        /// </summary>
+        /// <param name="fields">List of Fields to remove</param>
+        public override void RemoveFields(List<Field> fields)
+        {
+            // Remove common fields first
+            base.RemoveFields(fields);
+
+            // Remove the fields
+            if (fields.Contains(Field.Machine_Device_Instance_Name))
+                Name = null;
+
+            if (fields.Contains(Field.Machine_Device_Instance_BriefName))
+                BriefName = null;
+        }
+
+        /// <summary>
+        /// Set internal names to match One Rom Per Game (ORPG) logic
+        /// </summary>
+        public override void SetOneRomPerGame()
+        {
+            string[] splitname = Name.Split('.');
+            Machine.Name += $"/{string.Join(".", splitname.Take(splitname.Length > 1 ? splitname.Length - 1 : 1))}";
+            Name = Path.GetFileName(Name);
+        }
+
+        #endregion
+
+        #region Sorting and Merging
+
+        /// <summary>
+        /// Replace fields from another item
+        /// </summary>
+        /// <param name="item">DatItem to pull new information from</param>
+        /// <param name="fields">List of Fields representing what should be updated</param>
+        public override void ReplaceFields(DatItem item, List<Field> fields)
+        {
+            // Replace common fields first
+            base.ReplaceFields(item, fields);
+
+            // If we don't have a Instance to replace from, ignore specific fields
+            if (item.ItemType != ItemType.Instance)
+                return;
+
+            // Cast for easier access
+            Instance newItem = item as Instance;
+
+            // Replace the fields
+            if (fields.Contains(Field.Machine_Device_Instance_Name))
+                Name = newItem.Name;
+
+            if (fields.Contains(Field.Machine_Device_Instance_BriefName))
+                BriefName = newItem.BriefName;
+        }
+
+        #endregion
+    }
+}
diff --git a/SabreTools.Library/Tools/Converters.cs b/SabreTools.Library/Tools/Converters.cs
index df2e3e47..e2fed492 100644
--- a/SabreTools.Library/Tools/Converters.cs
+++ b/SabreTools.Library/Tools/Converters.cs
@@ -1684,6 +1684,8 @@ namespace SabreTools.Library.Tools
                     return ItemType.Extension;
                 case "feature":
                     return ItemType.Feature;
+                case "instance":
+                    return ItemType.Instance;
                 case "media":
                     return ItemType.Media;
                 case "ramoption":
@@ -1720,6 +1722,7 @@ namespace SabreTools.Library.Tools
                 "driver" => ItemType.Driver,
                 "extension" => ItemType.Extension,
                 "feature" => ItemType.Feature,
+                "instance" => ItemType.Instance,
                 "media" => ItemType.Media,
                 "ramoption" => ItemType.RamOption,
                 "release" => ItemType.Release,
@@ -2298,6 +2301,8 @@ namespace SabreTools.Library.Tools
                     return "extension";
                 case ItemType.Feature:
                     return "feature";
+                case ItemType.Instance:
+                    return "instance";
                 case ItemType.Media:
                     return "media";
                 case ItemType.RamOption:
@@ -2334,6 +2339,7 @@ namespace SabreTools.Library.Tools
                 ItemType.Driver => "driver",
                 ItemType.Extension => "extension",
                 ItemType.Feature => "feature",
+                ItemType.Instance => "instance",
                 ItemType.Media => "media",
                 ItemType.RamOption => "ramoption",
                 ItemType.Release => "release",