diff --git a/buffet/device_registration_info.cc b/buffet/device_registration_info.cc
index fb59f3b..07b902b 100644
--- a/buffet/device_registration_info.cc
+++ b/buffet/device_registration_info.cc
@@ -35,16 +35,17 @@
 namespace buffet {
 namespace storage_keys {
 
-// Persistent keys
+// Statically configured fields
+const char kApiKey[]        = "api_key";
 const char kClientId[]      = "client_id";
 const char kClientSecret[]  = "client_secret";
-const char kApiKey[]        = "api_key";
-const char kRefreshToken[]  = "refresh_token";
-const char kDeviceId[]      = "device_id";
 const char kOAuthURL[]      = "oauth_url";
 const char kServiceURL[]    = "service_url";
+// Credentials related to a particular registration.
+const char kDeviceId[]      = "device_id";
+const char kRefreshToken[]  = "refresh_token";
 const char kRobotAccount[]  = "robot_account";
-// Transient keys
+// Fields in our device metadata.
 const char kDeviceKind[]    = "device_kind";
 const char kName[]          = "name";
 const char kDisplayName[]   = "display_name";