diff --git a/SabreTools.Models/Internal/Header.cs b/SabreTools.Models/Internal/Header.cs
new file mode 100644
index 00000000..4d47fdc6
--- /dev/null
+++ b/SabreTools.Models/Internal/Header.cs
@@ -0,0 +1,153 @@
+namespace SabreTools.Models.Internal
+{
+    /// <summary>
+    /// Format-agnostic representation of metadata header data
+    /// </summary>
+    public class Header : DictionaryBase
+    {
+        #region Keys
+
+        /// <remarks>string</remarks>
+        public const string AuthorKey = "author";
+
+        /// <remarks>(none|split|merged|nonmerged|fullmerged|device|full) "split"</remarks>
+        public const string BiosModeKey = "biosmode";
+
+        /// <remarks>string</remarks>
+        public const string BuildKey = "build";
+
+        /// TODO: This needs an internal model OR mapping to fields
+        /// <remarks>CanOpen</remarks>
+        public const string CanOpenKey = "canOpen";
+
+        /// <remarks>string</remarks>
+        public const string CategoryKey = "category";
+
+        /// <remarks>string</remarks>
+        public const string CommentKey = "comment";
+
+        /// TODO: This needs an internal model OR mapping to fields
+        /// <remarks>Configuration</remarks>
+        public const string ConfigurationKey = "configuration";
+
+        /// <remarks>string</remarks>
+        public const string DateKey = "date";
+
+        /// <remarks>string</remarks>
+        public const string DatVersionKey = "datversion";
+
+        /// <remarks>(yes|no) "no"</remarks>
+        public const string DebugKey = "debug";
+
+        /// <remarks>string</remarks>
+        public const string DescriptionKey = "description";
+
+        /// <remarks>string</remarks>
+        public const string EmailKey = "email";
+
+        /// <remarks>string</remarks>
+        public const string EmulatorVersionKey = "emulatorversion";
+
+        /// <remarks>(none|split|merged|nonmerged|fullmerged|device|full) "split"</remarks>
+        public const string ForceMergingKey = "forcemerging";
+
+        /// <remarks>(obsolete|required|ignore) "obsolete"</remarks>
+        public const string ForceNodumpKey = "forcenodump";
+
+        /// <remarks>(zip|unzip) "zip"</remarks>
+        public const string ForcePackingKey = "forcepacking";
+
+        /// <remarks>(yes|no) "yes"</remarks>
+        public const string ForceZippingKey = "forcezipping";
+
+        /// <remarks>string, string[]</remarks>
+        public const string HeaderKey = "header";
+
+        /// <remarks>string</remarks>
+        public const string HomepageKey = "homepage";
+
+        /// <remarks>string</remarks>
+        public const string IdKey = "id";
+
+        /// TODO: This needs an internal model OR mapping to fields
+        /// <remarks>Search</remarks>
+        public const string ImagesKey = "images";
+
+        /// <remarks>string</remarks>
+        public const string ImFolderKey = "imFolder";
+
+        /// TODO: This needs an internal model OR mapping to fields
+        /// <remarks>Infos</remarks>
+        public const string InfosKey = "infos";
+
+        /// <remarks>(yes|no) "no"</remarks>
+        public const string LockBiosModeKey = "lockbiosmode";
+
+        /// <remarks>(yes|no) "no"</remarks>
+        public const string LockRomModeKey = "lockrommode";
+
+        /// <remarks>(yes|no) "no"</remarks>
+        public const string LockSampleModeKey = "locksamplemode";
+
+        /// <remarks>string</remarks>
+        public const string MameConfigKey = "mameconfig";
+
+        /// <remarks>string</remarks>
+        public const string NameKey = "name";
+
+        /// TODO: This needs an internal model OR mapping to fields
+        /// <remarks>NewDat</remarks>
+        public const string NewDatKey = "newDat";
+
+        /// <remarks>string</remarks>
+        public const string NoNamespaceSchemaLocationKey = "noNamespaceSchemaLocation";
+
+        /// <remarks>string</remarks>
+        public const string NotesKey = "notes";
+
+        /// <remarks>string</remarks>
+        public const string PluginKey = "plugin";
+
+        /// <remarks>string</remarks>
+        public const string RefNameKey = "refname";
+
+        /// <remarks>(none|split|merged|nonmerged|fullmerged|device|full) "split"</remarks>
+        public const string RomModeKey = "rommode";
+
+        /// <remarks>string</remarks>
+        public const string RomTitleKey = "romTitle";
+
+        /// <remarks>string</remarks>
+        public const string RootDirKey = "rootdir";
+
+        /// <remarks>(none|split|merged|nonmerged|fullmerged|device|full) "split"</remarks>
+        public const string SampleModeKey = "samplemode";
+
+        /// <remarks>string</remarks>
+        public const string ScreenshotsHeightKey = "screenshotsHeight";
+
+        /// <remarks>string</remarks>
+        public const string ScreenshotsWidthKey = "screenshotsWidth";
+
+        /// TODO: This needs an internal model OR mapping to fields
+        /// <remarks>Search</remarks>
+        public const string SearchKey = "search";
+
+        /// <remarks>string</remarks>
+        public const string SystemKey = "system";
+
+        /// <remarks>string</remarks>
+        public const string TimestampKey = "timestamp";
+
+        /// <remarks>string</remarks>
+        public const string TypeKey = "type";
+
+        /// <remarks>string</remarks>
+        public const string UrlKey = "url";
+
+        /// <remarks>string</remarks>
+        public const string VersionKey = "version";
+
+        #endregion
+    }
+}
\ No newline at end of file