diff --git a/policy/policy_contract.go b/policy/policy_contract.go
index dd5876b..39bb0ce 100644
--- a/policy/policy_contract.go
+++ b/policy/policy_contract.go
@@ -16,6 +16,8 @@ type Kind byte
 const (
 	Namespace = 'n'
 	Container = 'c'
+	User      = 'u'
+	Group     = 'g'
 	IAM       = 'i'
 )