diff --git a/docs/managed-code-analysis.md b/docs/managed-code-analysis.md
index eb2eeee18..72c55e6da 100644
--- a/docs/managed-code-analysis.md
+++ b/docs/managed-code-analysis.md
@@ -38,6 +38,12 @@ Inspect separately obtained components explicitly and preserve their identities.
 A valid implementation marker establishes a candidate native boundary, not
 recovered native semantics or runtime behavior.
 
+An assembly targeting [.NET Standard](https://learn.microsoft.com/en-us/dotnet/standard/net-standard)
+declares API compatibility across multiple .NET implementations. REA preserves
+that target in `target_frameworks` and leaves `runtime_family` as `unknown`
+unless independent markers identify a runtime family, such as a ReadyToRun
+signature.
+
 ### Resource admission
 
 The static provider admits regular input files up to 128 MiB before retaining
diff --git a/src/dotnet/ManagedArtifactInspector.ts b/src/dotnet/ManagedArtifactInspector.ts
index ca4824563..cd0d627b0 100644
--- a/src/dotnet/ManagedArtifactInspector.ts
+++ b/src/dotnet/ManagedArtifactInspector.ts
@@ -204,10 +204,7 @@ const runtimeFamilyFor = (
       file_offset: metadata.table(12)?.offset ?? null,
     });
   } else if (
-    frameworks.some(
-      (value) =>
-        value.startsWith(".NETCoreApp,") || value.startsWith(".NETStandard,"),
-    ) ||
+    frameworks.some((value) => value.startsWith(".NETCoreApp,")) ||
     cli.readyToRunSignature
   ) {
     runtimeFamily = "modern-dotnet";
@@ -226,6 +223,13 @@ const runtimeFamilyFor = (
           )
         : (metadata.table(12)?.offset ?? null),
     });
+  } else if (frameworks.some((value) => value.startsWith(".NETStandard,"))) {
+    evidence.push({
+      code: "target-framework-observed",
+      detail:
+        "An assembly-level TargetFrameworkAttribute names .NET Standard, an API specification that does not identify a runtime family.",
+      file_offset: metadata.table(12)?.offset ?? null,
+    });
   }
   return { runtime_family: runtimeFamily, evidence };
 };
diff --git a/tests/acceptance/managedCliOutput.test.ts b/tests/acceptance/managedCliOutput.test.ts
index be7506c85..a336a2a06 100644
--- a/tests/acceptance/managedCliOutput.test.ts
+++ b/tests/acceptance/managedCliOutput.test.ts
@@ -7,6 +7,56 @@ import { buildManagedPeFixture } from "../../src/dotnet/ManagedPe.fixture.js";
 import { createTestTempDirectory } from "../fixtures/temporaryDirectory.js";
 import { cliTest } from "../support/cli/cliFixture.js";
 
+cliTest(
+  "managed CLI separates .NET Standard API targets from runtime evidence",
+  async ({ cli }) => {
+    const root = await createTestTempDirectory("rea-managed-runtime-family-");
+    for (const [name, targetFramework, readyToRun, runtimeFamily] of [
+      ["standard", ".NETStandard,Version=v2.0", false, "unknown"],
+      ["core", ".NETCoreApp,Version=v8.0", false, "modern-dotnet"],
+      ["standard-r2r", ".NETStandard,Version=v2.0", true, "modern-dotnet"],
+    ] as const) {
+      const path = join(root, `${name}.dll`);
+      await writeFile(
+        path,
+        buildManagedPeFixture({ targetFramework, readyToRun }),
+      );
+      const result = await cli.run({
+        arguments: ["inspect-managed-artifact", path, "--json"],
+      });
+      expect(result.exitCode).toBe(0);
+      expect(result.json).toMatchObject({
+        operation: "inspect_managed_artifact",
+        subject: { local_path: path },
+        normalized_result: {
+          classification: {
+            status: "managed",
+            runtime_family: runtimeFamily,
+            implementation: readyToRun ? "cil-and-ready-to-run" : "cil",
+            evidence: expect.arrayContaining([
+              expect.objectContaining({
+                code: readyToRun
+                  ? "ready-to-run-signature-observed"
+                  : "target-framework-observed",
+                detail: expect.stringContaining(
+                  readyToRun
+                    ? "ReadyToRun signature"
+                    : name === "standard"
+                      ? "does not identify a runtime family"
+                      : "names modern .NET",
+                ),
+                file_offset: expect.any(Number),
+              }),
+            ]),
+          },
+          target_frameworks: [targetFramework],
+          coverage: { state: "complete", issues: [] },
+        },
+      });
+    }
+  },
+);
+
 cliTest(
   "managed CLI preserves evidence, filters, envelopes, and bounded token counts",
   async ({ cli }) => {