diff --git a/docs/project/list-of-diagnostics.md b/docs/project/list-of-diagnostics.md
index 928a53e0659ab..f80d9747319f7 100644
--- a/docs/project/list-of-diagnostics.md
+++ b/docs/project/list-of-diagnostics.md
@@ -110,6 +110,7 @@ The PR that reveals the implementation of the `<IncludeInternalObsoleteAttribute
 |  __`SYSLIB0053`__ | AesGcm should indicate the required tag size for encryption and decryption. Use a constructor that accepts the tag size. |
 |  __`SYSLIB0054`__ | Thread.VolatileRead and Thread.VolatileWrite are obsolete. Use Volatile.Read or Volatile.Write respectively instead. |
 |  __`SYSLIB0055`__ | The underlying hardware instruction does not perform a signed saturate narrowing operation, and it always returns an unsigned result. Use the unsigned overload instead. |
+|  __`SYSLIB0056`__ |  LoadFrom with a custom AssemblyHashAlgorithm is obsolete. Use overloads without an AssemblyHashAlgorithm. |
 |  __`SYSLIB0057`__ | Loading certificate data through the constructor or Import is obsolete. Use X509CertificateLoader instead to load certificates. |
 
 ## Analyzer Warnings
diff --git a/src/libraries/Common/src/System/Obsoletions.cs b/src/libraries/Common/src/System/Obsoletions.cs
index 764aab483cb79..922f84fb9ea2c 100644
--- a/src/libraries/Common/src/System/Obsoletions.cs
+++ b/src/libraries/Common/src/System/Obsoletions.cs
@@ -183,5 +183,8 @@ internal static class Obsoletions
 
         internal const string X509CtorCertDataObsoleteMessage = "Loading certificate data through the constructor or Import is obsolete. Use X509CertificateLoader instead to load certificates.";
         internal const string X509CtorCertDataObsoleteDiagId = "SYSLIB0057";
+
+        // When adding a new diagnostic ID, add it to the table in docs\project\list-of-diagnostics.md as well.
+        // Keep new const identifiers above this comment.
     }
 }