diff --git a/src/Microsoft.AspNet.DataProtection.Interfaces/DataProtectionExtensions.cs b/src/Microsoft.AspNet.DataProtection.Interfaces/DataProtectionExtensions.cs
index 393d9b5307..4a7312e43c 100644
--- a/src/Microsoft.AspNet.DataProtection.Interfaces/DataProtectionExtensions.cs
+++ b/src/Microsoft.AspNet.DataProtection.Interfaces/DataProtectionExtensions.cs
@@ -88,10 +88,17 @@ namespace Microsoft.AspNet.DataProtection
/// A unique application identifier, or null if is null
/// or cannot provide a unique application identifier.
///
+ ///
/// The returned identifier should be stable for repeated runs of this same application on
/// this machine. Additionally, the identifier is only unique within the scope of a single
/// machine, e.g., two different applications on two different machines may return the same
/// value.
+ ///
+ ///
+ /// This identifier may contain security-sensitive information such as physical file paths,
+ /// configuration settings, or other machine-specific information. Callers should take
+ /// special care not to disclose this information to untrusted entities.
+ ///
///
[EditorBrowsable(EditorBrowsableState.Never)]
public static string GetApplicationUniqueIdentifier(this IServiceProvider services)