diff --git a/MBS.Framework/MBS.Framework.csproj b/MBS.Framework/MBS.Framework.csproj
index f9a69f1..23da91c 100644
--- a/MBS.Framework/MBS.Framework.csproj
+++ b/MBS.Framework/MBS.Framework.csproj
@@ -112,6 +112,7 @@
     <Compile Include="CommandStylePreset.cs" />
     <Compile Include="Settings\CustomSetting.cs" />
     <Compile Include="CardinalDirection.cs" />
+    <Compile Include="TriState.cs" />
     <Compile Include="UserInterface\HorizontalAlignment.cs" />
     <Compile Include="UserInterface\VerticalAlignment.cs" />
     <Compile Include="CustomSettingsProvider.cs" />
diff --git a/MBS.Framework/TriState.cs b/MBS.Framework/TriState.cs
new file mode 100644
index 0000000..f8f7ea8
--- /dev/null
+++ b/MBS.Framework/TriState.cs
@@ -0,0 +1,30 @@
+//
+//  TriState.cs
+//
+//  Author:
+//       Michael Becker <alcexhim@gmail.com>
+//
+//  Copyright (c) 2021 Mike Becker's Software
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  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.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+using System;
+namespace MBS.Framework
+{
+	public enum TriState
+	{
+		Unspecified = -1,
+		False = 0,
+		True = 1
+	}
+}