Index: src/main/java/org/apache/jackrabbit/api/security/principal/GroupPrincipal.java
===================================================================
--- src/main/java/org/apache/jackrabbit/api/security/principal/GroupPrincipal.java	(nonexistent)
+++ src/main/java/org/apache/jackrabbit/api/security/principal/GroupPrincipal.java	(working copy)
@@ -0,0 +1,51 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.jackrabbit.api.security.principal;
+
+import java.security.Principal;
+import java.util.Enumeration;
+
+import org.osgi.annotation.versioning.ProviderType;
+
+/**
+ * This interface is used to represent a group of principals.
+ *
+ */
+@ProviderType
+public interface GroupPrincipal extends Principal {
+
+    /**
+     * Returns true if the passed principal is a member of the group.
+     * This method does a recursive search, so if a principal belongs to a
+     * group which is a member of this group, true is returned.
+     *
+     * @param member the principal whose membership is to be checked.
+     * @return true if the principal is a member of this group,
+     * false otherwise.
+     */
+    public boolean isMember(Principal member);
+
+    /**
+     * Returns an enumeration of the members in the group. The returned objects
+     * can be instances of either Principal or Group (which is a subclass of
+     * Principal).
+     *
+     * @return an enumeration of the group members.
+     */
+    public Enumeration<? extends Principal> members();
+
+}
Index: src/main/java/org/apache/jackrabbit/api/security/principal/PrincipalManager.java
===================================================================
--- src/main/java/org/apache/jackrabbit/api/security/principal/PrincipalManager.java	(revision 1820891)
+++ src/main/java/org/apache/jackrabbit/api/security/principal/PrincipalManager.java	(working copy)
@@ -17,7 +17,6 @@
 package org.apache.jackrabbit.api.security.principal;
 
 import java.security.Principal;
-import java.security.acl.Group;
 
 /**
  * This interface defines the principal manager which is the clients view on
@@ -42,7 +41,7 @@
 
     /**
      * Filter flag indicating that only <code>Principal</code>s that do NOT
-     * represent a {@link java.security.acl.Group group} should be searched
+     * represent a {@link org.apache.jackrabbit.api.security.principal.GroupPrincipal group} should be searched
      * and returned.
      */
     int SEARCH_TYPE_NOT_GROUP = 1;
@@ -49,7 +48,7 @@
 
     /**
      * Filter flag indicating that only <code>Principal</code>s that represent
-     * a {@link java.security.acl.Group group} of Principals should be searched
+     * a {@link org.apache.jackrabbit.api.security.principal.GroupPrincipal group} of Principals should be searched
      * and returned.
      */
     int SEARCH_TYPE_GROUP = 2;
Index: src/main/java/org/apache/jackrabbit/api/security/principal/package-info.java
===================================================================
--- src/main/java/org/apache/jackrabbit/api/security/principal/package-info.java	(revision 1820891)
+++ src/main/java/org/apache/jackrabbit/api/security/principal/package-info.java	(working copy)
@@ -18,5 +18,5 @@
 /**
  * Jackrabbit extensions for JAAS principals.
  */
-@org.osgi.annotation.versioning.Version("2.3")
+@org.osgi.annotation.versioning.Version("2.4.0")
 package org.apache.jackrabbit.api.security.principal;