diff --git a/pkg/consts/spd.go b/pkg/consts/spd.go
index 27c3895..d6ba5d3 100644
--- a/pkg/consts/spd.go
+++ b/pkg/consts/spd.go
@@ -29,3 +29,12 @@ const (
 
 	WorkloadAnnotationSPDNameKey = "spd.katalyst.kubewharf.io/name"
 )
+
+// const variables for spd annotations.
+const (
+	// SPDAnnotationBaselinePercentileKey is updated by the SPD controller. It represents
+	// the baseline percentile across all pods managed by this SPD. Agents or controllers
+	// can use this key to determine if a pod falls within the baseline by comparing it
+	// with the pod's baseline coefficient.
+	SPDAnnotationBaselinePercentileKey = "spd.katalyst.kubewharf.io/baselinePercentile"
+)
diff --git a/pkg/utils/topology_policy.go b/pkg/utils/topology_policy.go
index 18b2c96..82eec96 100644
--- a/pkg/utils/topology_policy.go
+++ b/pkg/utils/topology_policy.go
@@ -1,3 +1,19 @@
+/*
+Copyright 2022 The Katalyst Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 package utils
 
 import (