diff --git a/metagpt/roles/qa_engineer.py b/metagpt/roles/qa_engineer.py
index b83ab6e21..5cc35a878 100644
--- a/metagpt/roles/qa_engineer.py
+++ b/metagpt/roles/qa_engineer.py
@@ -4,7 +4,8 @@
 @Time    : 2023/5/11 14:43
 @Author  : alexanderwu
 @File    : qa_engineer.py
-@Modified By: mashenquan, 2023-11-1. Standardize the usage of message filtering-related features.
+@Modified By: mashenquan, 2023-11-1. In accordance with Chapter 2.2.1 and 2.2.2 of RFC 116, modify the data
+        type of the `cause_by` value in the `Message` to a string, and utilize the new message filtering feature.
 """
 import os
 from pathlib import Path
diff --git a/metagpt/roles/researcher.py b/metagpt/roles/researcher.py
index 6e89b9fe7..4ec6f31e1 100644
--- a/metagpt/roles/researcher.py
+++ b/metagpt/roles/researcher.py
@@ -1,6 +1,7 @@
 #!/usr/bin/env python
 """
-@Modified By: mashenquan, 2023-11-1. Standardize the usage of message filtering-related features.
+@Modified By: mashenquan, 2023-11-1. According to Chapter 2.2.1 and 2.2.2 of RFC 116, change the data type of
+        the `cause_by` value in the `Message` to a string to support the new message distribution feature.
 """
 
 
diff --git a/metagpt/roles/role.py b/metagpt/roles/role.py
index 318b7d7a8..79a9fb2de 100644
--- a/metagpt/roles/role.py
+++ b/metagpt/roles/role.py
@@ -4,7 +4,7 @@
 @Time    : 2023/5/11 14:42
 @Author  : alexanderwu
 @File    : role.py
-@Modified By: mashenquan, 2023-11-1. Optimization:
+@Modified By: mashenquan, 2023-11-1. According to Chapter 2.2.1 and 2.2.2 of RFC 116:
     1. Merge the `recv` functionality into the `_observe` function. Future message reading operations will be
     consolidated within the `_observe` function.
     2. Standardize the message filtering for string label matching. Role objects can access the message labels