diff --git a/private/attributes b/private/attributes
index 77143a3..fe50b0d 100644
--- a/private/attributes
+++ b/private/attributes
@@ -13,4 +13,5 @@
 
 # All SDK sandbox domains
 attribute sdk_sandbox_all;
-
+# The SDK sandbox domains for the current SDK level.
+attribute sdk_sandbox_current;