diff --git a/service/src/com/android/server/connectivity/ClatCoordinator.java b/service/src/com/android/server/connectivity/ClatCoordinator.java
index f333dae..e808746 100644
--- a/service/src/com/android/server/connectivity/ClatCoordinator.java
+++ b/service/src/com/android/server/connectivity/ClatCoordinator.java
@@ -256,6 +256,7 @@
         @Nullable
         public IBpfMap<ClatIngress6Key, ClatIngress6Value> getBpfIngress6Map() {
             try {
+                // written from clatd.c
                 return new BpfMap<>(CLAT_INGRESS6_MAP_PATH,
                        ClatIngress6Key.class, ClatIngress6Value.class);
             } catch (ErrnoException e) {
@@ -268,6 +269,7 @@
         @Nullable
         public IBpfMap<ClatEgress4Key, ClatEgress4Value> getBpfEgress4Map() {
             try {
+                // written from clatd.c
                 return new BpfMap<>(CLAT_EGRESS4_MAP_PATH,
                        ClatEgress4Key.class, ClatEgress4Value.class);
             } catch (ErrnoException e) {
@@ -280,6 +282,7 @@
         @Nullable
         public IBpfMap<CookieTagMapKey, CookieTagMapValue> getBpfCookieTagMap() {
             try {
+                // also read and written from other locations
                 return new BpfMap<>(COOKIE_TAG_MAP_PATH,
                        CookieTagMapKey.class, CookieTagMapValue.class);
             } catch (ErrnoException e) {