diff --git a/src/raspberrypi/rascsi_interface.proto b/src/raspberrypi/rascsi_interface.proto
index 001c74d7..88160a78 100644
--- a/src/raspberrypi/rascsi_interface.proto
+++ b/src/raspberrypi/rascsi_interface.proto
@@ -162,7 +162,8 @@ enum PbOperation {
 // The operation parameter meta data
 message PbOperationParameter {
     string name = 1;
-    // Optional short localized description, key is the lower case locale (e.g. en, de)
+    // Optional short localized description, key is the lower case locale (e.g. en, de).
+    // Falling back to "en" is recommended if a description for a different language is missing.
     map<string, string> description = 2;
     // "string", "int", or "boolean". Parameters are always strings but must be convertible to these types.
     string type = 3;
@@ -174,7 +175,8 @@ message PbOperationParameter {
 // The list of parameters supported by an operation
 message PbOperationParameters {
     string name = 1;
-    // Optional short localized description, key is the lower case locale (e.g. en, de)
+    // Optional short localized description, key is the lower case locale (e.g. en, de).
+    // Falling back to "en" is recommended if a description for a different language is missing.
     map<string, string> description = 2;
     repeated PbOperationParameter parameters = 3;
 }