diff --git a/ChangeLog b/ChangeLog
index b129330755..abff258f85 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue Oct 21 15:56:56 2014  Martin Duerst <duerst@it.aoyama.ac.jp>
+
+	* lib/unicode_normalize/normalize.rb: Added comment to point to
+	  relevant portion of Unicode standard for Hangul (de)composition
+	  identifiers and algorithm.
+
 Tue Oct 21 11:49:16 2014  Andreas Schwab  <schwab@suse.de>
 
 	* gc.c (mark_current_machine_context) [__mc68000__]: Update stack
diff --git a/lib/unicode_normalize/normalize.rb b/lib/unicode_normalize/normalize.rb
index bd53078c33..97aaeddbee 100644
--- a/lib/unicode_normalize/normalize.rb
+++ b/lib/unicode_normalize/normalize.rb
@@ -27,6 +27,8 @@ module UnicodeNormalize
                        end
 
   ## Constants For Hangul
+  # for details such as the meaning of the identifiers below, please see
+  # http://www.unicode.org/versions/Unicode7.0.0/ch03.pdf, pp. 144/145
   SBASE = 0xAC00
   LBASE = 0x1100
   VBASE = 0x1161