diff --git a/rhinocommon/cs/SampleCsEventWatcher/Properties/AssemblyInfo.cs b/rhinocommon/cs/SampleCsEventWatcher/Properties/AssemblyInfo.cs
new file mode 100644
index 00000000..cd760f8e
--- /dev/null
+++ b/rhinocommon/cs/SampleCsEventWatcher/Properties/AssemblyInfo.cs
@@ -0,0 +1,18 @@
+using Rhino.PlugIns;
+using System.Reflection;
+using System.Runtime.InteropServices;
+
+[assembly: PlugInDescription(DescriptionType.Address, "146 North Canal Street, Suite 320\r\nSeattle, WA 98103")]
+[assembly: PlugInDescription(DescriptionType.Country, "United States")]
+[assembly: PlugInDescription(DescriptionType.Email, "dale@mcneel.com")]
+[assembly: PlugInDescription(DescriptionType.Phone, "206-545-6877")]
+[assembly: PlugInDescription(DescriptionType.Fax, "206-545-7321")]
+[assembly: PlugInDescription(DescriptionType.Organization, "Robert McNeel & Associates")]
+[assembly: PlugInDescription(DescriptionType.UpdateUrl, "https://github.com/mcneel/rhino-developer-samples")]
+[assembly: PlugInDescription(DescriptionType.WebSite, "https://github.com/mcneel/rhino-developer-samples")]
+[assembly: PlugInDescription(DescriptionType.Icon, "SampleCsEventWatcher.Resources.SampleCs.ico")]
+
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+[assembly: ComVisible(false)]
+[assembly: Guid("934955FB-33BB-4F6C-9F9E-9B0927854AAE")]
diff --git a/rhinocommon/cs/SampleCsUserData/Commands/SampleCsAddGroupUserData.cs b/rhinocommon/cs/SampleCsUserData/Commands/SampleCsAddGroupUserData.cs
new file mode 100644
index 00000000..0cb66841
--- /dev/null
+++ b/rhinocommon/cs/SampleCsUserData/Commands/SampleCsAddGroupUserData.cs
@@ -0,0 +1,34 @@
+using Rhino;
+using Rhino.Commands;
+
+namespace SampleCsUserData.Commands
+{
+  public class SampleCsAddGroupUserData : Command
+  {
+    public override string EnglishName => "SampleCsAddGroupUserData";
+
+    protected override Result RunCommand(RhinoDoc doc, RunMode mode)
+    {
+      var group = doc.Groups.FindIndex(0);
+      if (null == group)
+      {
+        RhinoApp.WriteLine("No groups found in the document.");
+        return Result.Success;
+      }
+
+      var ud = group.UserData.Find(typeof(SampleCsUserDataObject)) as SampleCsUserDataObject;
+      if (null == ud)
+      {
+        ud = new SampleCsUserDataObject { Notes = "Hello Rhino Group!" };
+        group.UserData.Add(ud);
+        RhinoApp.WriteLine("{0} added", ud.Description);
+      }
+      else
+      {
+        RhinoApp.WriteLine("{0} = {1}", ud.Description, ud.Notes);
+      }
+
+      return Result.Success;
+    }
+  }
+}
\ No newline at end of file
diff --git a/rhinocommon/cs/SampleCsUserData/Properties/AssemblyInfo.cs b/rhinocommon/cs/SampleCsUserData/Properties/AssemblyInfo.cs
new file mode 100644
index 00000000..d2aa4377
--- /dev/null
+++ b/rhinocommon/cs/SampleCsUserData/Properties/AssemblyInfo.cs
@@ -0,0 +1,18 @@
+using Rhino.PlugIns;
+using System.Reflection;
+using System.Runtime.InteropServices;
+
+[assembly: PlugInDescription(DescriptionType.Address, "146 North Canal Street, Suite 320\r\nSeattle, WA 98103")]
+[assembly: PlugInDescription(DescriptionType.Country, "United States")]
+[assembly: PlugInDescription(DescriptionType.Email, "dale@mcneel.com")]
+[assembly: PlugInDescription(DescriptionType.Phone, "206-545-6877")]
+[assembly: PlugInDescription(DescriptionType.Fax, "206-545-7321")]
+[assembly: PlugInDescription(DescriptionType.Organization, "Robert McNeel & Associates")]
+[assembly: PlugInDescription(DescriptionType.UpdateUrl, "https://github.com/mcneel/rhino-developer-samples")]
+[assembly: PlugInDescription(DescriptionType.WebSite, "https://github.com/mcneel/rhino-developer-samples")]
+[assembly: PlugInDescription(DescriptionType.Icon, "SampleCsUserData.Resources.SampleCs.ico")]
+
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+[assembly: ComVisible(false)]
+[assembly: Guid("8A62C7AE-3C24-4151-BCD0-AAB36C7DCA8B")]
diff --git a/rhinocommon/cs/SamplesCs.sln b/rhinocommon/cs/SamplesCs.sln
index a3689293..a796e28d 100644
--- a/rhinocommon/cs/SamplesCs.sln
+++ b/rhinocommon/cs/SamplesCs.sln
@@ -1,4 +1,3 @@
-
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
 VisualStudioVersion = 17.8.34408.163
@@ -29,11 +28,11 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SampleCsTest2", "SampleCsSh
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SampleCsSkin", "SampleCsSkin\SampleCsSkin.csproj", "{4E0FCE1B-4577-4F25-86FC-2F1526D2C7CB}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SampleCsUserData", "SampleCsUserData\SampleCsUserData.csproj", "{444482E8-CB8F-4A79-87A8-9C3FCBCC7B16}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SampleCsUserData", "SampleCsUserData\SampleCsUserData.csproj", "{444482E8-CB8F-4A79-87A8-9C3FCBCC7B16}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SampleCsWpf", "SampleCsWpf\SampleCsWpf.csproj", "{098AF3EE-CF77-4FEF-859B-B3BC22C7336A}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SampleCsEto", "SampleCsEto\SampleCsEto.csproj", "{CD962975-5E0A-4BB7-AF01-ABD4A9E18AAC}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SampleCsEto", "SampleCsEto\SampleCsEto.csproj", "{CD962975-5E0A-4BB7-AF01-ABD4A9E18AAC}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SampleCsCollapsibleSectionETOUI", "SampleCsCollapsibleSectionETO_UI\SampleCsCollapsibleSectionETOUI.csproj", "{D36880D5-3106-4D36-A9AB-E446E5C5781D}"
 EndProject