diff --git a/.props/_GlobalStaticVersion.props b/.props/_GlobalStaticVersion.props
index 9cc616c89d..dfb498f35c 100644
--- a/.props/_GlobalStaticVersion.props
+++ b/.props/_GlobalStaticVersion.props
@@ -14,6 +14,7 @@
     <SemanticVersionMinor>18</SemanticVersionMinor> <!-- If changing the Minor version, also update the Date value. -->
     <SemanticVersionPatch>0</SemanticVersionPatch>
     <PreReleaseMilestone></PreReleaseMilestone> <!--Valid values: beta1, beta2, EMPTY for stable -->
+    <PreReleaseMilestone Condition="'$(Redfield)' == 'True'">redfield</PreReleaseMilestone>
     <PreReleaseMilestone Condition="'$(NightlyBuild)' == 'True'">nightly</PreReleaseMilestone> <!-- Overwrite this property for nightly builds from the DEVELOP branch. -->
     <!-- 
       Date when Semantic Version was changed. 
diff --git a/BASE/Test/Microsoft.ApplicationInsights.Test/Microsoft.ApplicationInsights.Tests/Extensibility/Implementation/Tracing/CoreEventSourceTest.cs b/BASE/Test/Microsoft.ApplicationInsights.Test/Microsoft.ApplicationInsights.Tests/Extensibility/Implementation/Tracing/CoreEventSourceTest.cs
index 28e83e46c2..26088e82bb 100644
--- a/BASE/Test/Microsoft.ApplicationInsights.Test/Microsoft.ApplicationInsights.Tests/Extensibility/Implementation/Tracing/CoreEventSourceTest.cs
+++ b/BASE/Test/Microsoft.ApplicationInsights.Test/Microsoft.ApplicationInsights.Tests/Extensibility/Implementation/Tracing/CoreEventSourceTest.cs
@@ -4,6 +4,7 @@
     using Microsoft.ApplicationInsights.TestFramework;
     using System.Diagnostics.Tracing;
     using Microsoft.VisualStudio.TestTools.UnitTesting;
+    using System.Linq;
 
     [TestClass]
     public class CoreEventSourceTest
@@ -25,5 +26,30 @@ private static EventAttribute GetEventAttribute(string methodName)
             MethodInfo method = typeof(CoreEventSource).GetMethod(methodName);
             return method.GetCustomAttribute<EventAttribute>();
         }
+
+#if REDFIELD
+        /// <summary>
+        /// This is a sanitiy check.
+        /// The 'Redfield' compilation flag should switch the name of EventSource class.
+        /// Devs can review the test log and confirm that this test runs and passes.
+        /// This will serve as a verification that the Redfield compilation flag worked as expected.
+        /// 
+        /// To run this test:
+        /// dotnet build /p:Redfield=True ".\dotnet\BASE\Microsoft.ApplicationInsights.sln"
+        /// dotnet test ".\bin\Debug\test\Microsoft.ApplicationInsights.Tests\net5.0\Microsoft.ApplicationInsights.Tests.dll" --filter Name~VerifyRedfieldEventSourceName
+        /// </summary>
+        [TestMethod]
+        public void VerifyRedfieldEventSourceName()
+        {
+            var expectedName = "Redfield-Microsoft-ApplicationInsights-Core";
+
+            var eventSourceAttribute = typeof(CoreEventSource)
+                .GetCustomAttributes(typeof(EventSourceAttribute))
+                .Single() as EventSourceAttribute;
+
+            Assert.IsNotNull(eventSourceAttribute);
+            Assert.AreEqual(expectedName, eventSourceAttribute.Name);
+        }
+#endif
     }
-}
\ No newline at end of file
+}
diff --git a/BASE/src/Microsoft.ApplicationInsights/Extensibility/Implementation/Tracing/CoreEventSource.cs b/BASE/src/Microsoft.ApplicationInsights/Extensibility/Implementation/Tracing/CoreEventSource.cs
index fcdec90df0..c199cdf202 100644
--- a/BASE/src/Microsoft.ApplicationInsights/Extensibility/Implementation/Tracing/CoreEventSource.cs
+++ b/BASE/src/Microsoft.ApplicationInsights/Extensibility/Implementation/Tracing/CoreEventSource.cs
@@ -4,7 +4,11 @@
     using System.Diagnostics.CodeAnalysis;
     using System.Diagnostics.Tracing;
 
+#if REDFIELD
+    [EventSource(Name = "Redfield-Microsoft-ApplicationInsights-Core")]
+#else
     [EventSource(Name = "Microsoft-ApplicationInsights-Core")]
+#endif
     [SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", Justification = "appDomainName is required")]
     internal sealed class CoreEventSource : EventSource
     {
diff --git a/BASE/src/Microsoft.ApplicationInsights/Microsoft.ApplicationInsights.csproj b/BASE/src/Microsoft.ApplicationInsights/Microsoft.ApplicationInsights.csproj
index 7974809bbd..0adc47fc4b 100644
--- a/BASE/src/Microsoft.ApplicationInsights/Microsoft.ApplicationInsights.csproj
+++ b/BASE/src/Microsoft.ApplicationInsights/Microsoft.ApplicationInsights.csproj
@@ -23,9 +23,21 @@
     <PackageReference Include="Microsoft.Diagnostics.Tracing.EventRegister" Version="1.1.28" Condition="$(OS) == 'Windows_NT'">
       <PrivateAssets>All</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="5.0.0" />
   </ItemGroup>
 
+  <Choose>
+    <When Condition="'$(Redfield)' == 'True'">
+      <ItemGroup>
+        <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="4.7.0" />
+      </ItemGroup>
+    </When>
+    <Otherwise>
+      <ItemGroup>
+        <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="5.0.0" />
+      </ItemGroup>
+    </Otherwise>
+  </Choose>
+  
   <ItemGroup Condition="'$(TargetFramework)' != 'netstandard2.0'">
     <Reference Include="System.Net.Http" />
   </ItemGroup>
diff --git a/Directory.Build.props b/Directory.Build.props
index e141f830f0..ef0d9c5ccc 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -7,8 +7,20 @@
 
     <!-- This is used to disable some build properties. -->
     <IsExamplesSolution Condition="'$(SolutionName)' == 'Examples' ">true</IsExamplesSolution>
+
+    <!-- This is used to change EventSource names. -->
+    <DefineConstants Condition="'$(Redfield)' == 'True'">$(DefineConstants);REDFIELD</DefineConstants>
   </PropertyGroup>
 
+  <Target Name="Info_Redfield"  BeforeTargets="Build" Condition="'$(Redfield)' == 'True'">
+    <!-- 
+    This flag is reserved for Codeless Attach products.
+    Redfield has some unique code changes to avoid conflicting with the real AI SDK.
+    To use: dotnet build /p:Redfield=True
+    -->
+    <Message Text="Directory.Build.props: Redfield build detected." Importance="high"/>
+  </Target>
+
   <Target Name="Info_InternalSettings"  BeforeTargets="Build">
     <Message Text="Directory.Build.props: Internal_Logging is set to $(Internal_Logging)." Importance="high"/>
   </Target>