diff --git a/resources/rendertheme.xsd b/resources/rendertheme.xsd
index 0bf0aac9..37ddc337 100644
--- a/resources/rendertheme.xsd
+++ b/resources/rendertheme.xsd
@@ -237,6 +237,8 @@
         <xs:attribute name="symbol-width" type="xs:positiveInteger" use="optional" />
         <xs:attribute name="symbol-height" type="xs:positiveInteger" use="optional" />
         <xs:attribute name="symbol-percent" type="xs:positiveInteger" use="optional" />
+
+        <!-- symbols on lines -->
         <xs:attribute name="billboard" default="false" type="xs:boolean" use="optional" />
         <xs:attribute name="repeat" default="false" type="xs:boolean" use="optional" />
         <xs:attribute name="repeat-gap" default="200" type="xs:float" use="optional" />
diff --git a/vtm/src/org/oscim/theme/styles/SymbolStyle.java b/vtm/src/org/oscim/theme/styles/SymbolStyle.java
index 2267426a..ce185652 100644
--- a/vtm/src/org/oscim/theme/styles/SymbolStyle.java
+++ b/vtm/src/org/oscim/theme/styles/SymbolStyle.java
@@ -39,6 +39,7 @@ public final class SymbolStyle extends RenderStyle<SymbolStyle> {
     public final int symbolHeight;
     public final int symbolPercent;
 
+    // Symbols on lines
     public final boolean billboard;
     public final boolean repeat;
     public final float repeatStart;
@@ -122,6 +123,7 @@ public final class SymbolStyle extends RenderStyle<SymbolStyle> {
         public int symbolHeight;
         public int symbolPercent;
 
+        // Symbols on lines
         public boolean billboard;
         public boolean repeat;
         public float repeatStart;