diff --git a/src/backend/utils/mb/Unicode/UCS_to_GB18030.pl b/src/backend/utils/mb/Unicode/UCS_to_GB18030.pl
index da9308a7dd5e66561c16e206a6fa162d1e12ac81..e0730beb1faf8dce4c46d9ddff3a40072eb22f58 100755
--- a/src/backend/utils/mb/Unicode/UCS_to_GB18030.pl
+++ b/src/backend/utils/mb/Unicode/UCS_to_GB18030.pl
@@ -5,7 +5,8 @@
 # src/backend/utils/mb/Unicode/UCS_to_GB18030.pl
 #
 # Generate UTF-8 <--> GB18030 code conversion tables from
-# "gb-18030-2000.xml"
+# "gb-18030-2000.xml", obtained from
+# http://source.icu-project.org/repos/icu/data/trunk/charset/data/xml/
 #
 # The lines we care about in the source file look like
 #    <a u="009A" b="81 30 83 36"/>
diff --git a/src/backend/utils/mb/Unicode/gb18030_to_utf8.map b/src/backend/utils/mb/Unicode/gb18030_to_utf8.map
index 5d08e1197d37f9d9546dcba7ef5d7adbcc67b2b6..0e2f94759b2c36ec3b3acf3a7e0179309a525194 100644
--- a/src/backend/utils/mb/Unicode/gb18030_to_utf8.map
+++ b/src/backend/utils/mb/Unicode/gb18030_to_utf8.map
@@ -1,3 +1,5 @@
+/* src/backend/utils/mb/Unicode/gb18030_to_utf8.map */
+
 static const pg_local_to_utf LUmapGB18030[ 30733 ] = {
   {0x8140, 0xe4b882},
   {0x8141, 0xe4b884},
diff --git a/src/backend/utils/mb/Unicode/utf8_to_gb18030.map b/src/backend/utils/mb/Unicode/utf8_to_gb18030.map
index 87e6e3d1bd949d78b88f65677cc8158ead8ba6df..7edce78ced574a46e7332c7c5bb55b0e727a63ed 100644
--- a/src/backend/utils/mb/Unicode/utf8_to_gb18030.map
+++ b/src/backend/utils/mb/Unicode/utf8_to_gb18030.map
@@ -1,3 +1,5 @@
+/* src/backend/utils/mb/Unicode/utf8_to_gb18030.map */
+
 static const pg_utf_to_local ULmapGB18030[ 30733 ] = {
   {0xc280, 0x81308130},
   {0xc281, 0x81308131},