diff --git a/conf/app.conf b/conf/app.conf
index f76bde913..897c11e59 100644
--- a/conf/app.conf
+++ b/conf/app.conf
@@ -8,7 +8,7 @@ enableAdmin = true
 
 apiVersion = 1.8.0
 ignoredArticles="The El La Los Las Le Les Os As O A"
-indexGroups=A B C D E F G H I J K L M N O P Q R S T U V W X-Z(XYZ)
+indexGroups=A B C D E F G H I J K L M N O P Q R S T U V W X-Z(XYZ) [Unknown]([)
 
 musicFolder=./iTunes1.xml
 user=deluan