diff --git a/internal/proto/analytics/connections_log.proto b/internal/proto/analytics/connections_log.proto
index 8095c996..e0aa6a85 100644
--- a/internal/proto/analytics/connections_log.proto
+++ b/internal/proto/analytics/connections_log.proto
@@ -37,7 +37,7 @@ message ConnectionsLog {
   optional ClientSession client_session = 2;
 
   // The version of Nearby Connections. E.g. "v1.0.4".
-  optional string version = 3;
+  optional string version = 3 /* type = ST_SOFTWARE_ID */;
 
   // For EventType.ERROR_CODE
   optional ErrorCode error_code = 4;
@@ -98,7 +98,8 @@ message ConnectionsLog {
 
     // The build version of the user's device (Same value as the Build number in
     // Settings -> about phone).
-    optional string build_version = 10;
+    optional string build_version = 10
+        /* type = ST_SOFTWARE_ID */;
   }
 
   // Encapsulates activity during a period of discovery.
@@ -121,7 +122,7 @@ message ConnectionsLog {
     repeated UwbRangingProcess uwb_ranging = 5;
 
     // The SendingEvent flow id.
-    optional int64 client_flow_id = 6;
+    optional int64 client_flow_id = 6 /* type = ST_SESSION_ID */;
 
     // Encapsulates additional discovery information.
     optional DiscoveryMetadata discovery_metadata = 7;
@@ -199,7 +200,7 @@ message ConnectionsLog {
     repeated ConnectionRequest received_connection_request = 3;
 
     // The ReceivingEvent flow id.
-    optional int64 client_flow_id = 4;
+    optional int64 client_flow_id = 4 /* type = ST_SESSION_ID */;
 
     // Encapsulates additional advertising information.
     optional AdvertisingMetadata advertising_metadata = 5;
@@ -228,7 +229,7 @@ message ConnectionsLog {
         remote_response = 4;
 
     // The SendingEvent flow id.
-    optional int64 client_flow_id = 5;
+    optional int64 client_flow_id = 5 /* type = ST_SESSION_ID */;
   }
 
   // An attempt to connect to an endpoint over a particular medium.
@@ -252,10 +253,11 @@ message ConnectionsLog {
         attempt_result = 5;
 
     // The ReceivingEvent flow id.
-    optional int64 client_flow_id = 6;
+    optional int64 client_flow_id = 6 /* type = ST_SESSION_ID */;
 
     // The token used to identify this connection pair.
-    optional string connection_token = 7;
+    optional string connection_token = 7
+        /* type = ST_SESSION_ID */;
 
     // Encapsulates additional connection information.
     optional ConnectionAttemptMetadata connection_attempt_metadata = 8;
@@ -280,10 +282,11 @@ message ConnectionsLog {
         disconnection_reason = 5;
 
     // The SendingEvent flow id.
-    optional int64 client_flow_id = 6;
+    optional int64 client_flow_id = 6 /* type = ST_SESSION_ID */;
 
     // The token use to identify this established connection.
-    optional string connection_token = 7;
+    optional string connection_token = 7
+        /* type = ST_SESSION_ID */;
 
     // The type of established connection.
     optional location.nearby.proto.connections.ConnectionAttemptType type = 8;
@@ -334,10 +337,11 @@ message ConnectionsLog {
         error_stage = 6;
 
     // The SendingEvent flow id.
-    optional int64 client_flow_id = 7;
+    optional int64 client_flow_id = 7 /* type = ST_SESSION_ID */;
 
     // The token used to identify this upgrade pair.
-    optional string connection_token = 8;
+    optional string connection_token = 8
+        /* type = ST_SESSION_ID */;
   }
 
   // Next Id: 22
@@ -353,7 +357,7 @@ message ConnectionsLog {
     // The error description.
     optional location.nearby.errorcode.proto.Description description = 5;
     // The flow id which the error occurs on.
-    optional int64 flow_id = 6;
+    optional int64 flow_id = 6 /* type = ST_SESSION_ID */;
 
     // Error code value
     oneof ErrorCodeDetail {
@@ -383,7 +387,8 @@ message ConnectionsLog {
     }
 
     // The token use to identify this established connection.
-    optional string connection_token = 16;
+    optional string connection_token = 16
+        /* type = ST_SESSION_ID */;
   }
 
   // Some additional information to keep with the advertising phase.
@@ -433,13 +438,14 @@ message ConnectionsLog {
 
     // The MCC (Mobile country code) MNC (Mobile network code) of the network
     // operator.
-    optional string network_operator = 4;
+    optional string network_operator = 4
+        /* type = ST_LOCATION */;
 
     // The upper-case ISO 3166-1 alpha-2 country code of:
     // 1. the current connected WiFi network
     // 2. or the current registered operator's MCC (Mobile Country Code)
     // 3. or empty string.
-    optional string country_code = 5;
+    optional string country_code = 5 /* type = ST_LOCATION */;
 
     // The TDLS status used by the wifi lan medium,
     // TDLS, shortened from Tunneled Direct Link Setup, is "a seamless way to
diff --git a/proto/mediums/nfc_frames.proto b/proto/mediums/nfc_frames.proto
index 8dcf0183..44ee520c 100644
--- a/proto/mediums/nfc_frames.proto
+++ b/proto/mediums/nfc_frames.proto
@@ -27,7 +27,7 @@ message AdvertisementData {
   optional bytes tag = 1;
 
   // A public key associated with the advertisement.
-  optional bytes public_key = 2;
+  optional bytes public_key = 2 /* type = ST_SECURITY_KEY */;
 }
 
 // The data to be sent to advertisers from scanning device during discovery.
@@ -39,5 +39,5 @@ message AdvertisementRequest {
   optional string endpoint_id = 2;
 
   // Public key from the scanning device.
-  optional bytes public_key = 3;
+  optional bytes public_key = 3 /* type = ST_SECURITY_KEY */;
 }