diff --git a/vtm/src/org/oscim/theme/rule/NegativeMatcher.java b/vtm/src/org/oscim/theme/rule/NegativeMatcher.java
index b9f78cb0..9fec9cf3 100644
--- a/vtm/src/org/oscim/theme/rule/NegativeMatcher.java
+++ b/vtm/src/org/oscim/theme/rule/NegativeMatcher.java
@@ -22,13 +22,16 @@ class NegativeMatcher implements AttributeMatcher {
 	private final String[] mKeyList;
 	private final String[] mValueList;
 
-	// - exclusive negation matches when either KEY is not present
+	// (-) 'exclusive negation' matches when either KEY is not present
 	//   or KEY is present and any VALUE is NOT present
 	//
-	// - non-exclusive negation matches when either KEY is not present
+	// (\) 'except negation' matches when KEY is present
+	//   none items of VALUE is present (TODO).
+	//   (can be emulated by <m k="a"><m k=a v="-|b|c">...</m></m>)
+	//
+	// (~) 'non-exclusive negation' matches when either KEY is not present
 	//   or KEY is present and any VALUE is present
 	//
-	// - TODO 'MUST NOT contain key'
 	private final boolean mExclusive;
 
 	NegativeMatcher(List<String> keyList, List<String> valueList, boolean exclusive) {