diff --git a/src/main/java/ch/ethz/seb/sebserver/gbl/model/exam/ClientGroupData.java b/src/main/java/ch/ethz/seb/sebserver/gbl/model/exam/ClientGroupData.java
index 35fb2586..ef6553d6 100644
--- a/src/main/java/ch/ethz/seb/sebserver/gbl/model/exam/ClientGroupData.java
+++ b/src/main/java/ch/ethz/seb/sebserver/gbl/model/exam/ClientGroupData.java
@@ -10,23 +10,26 @@ package ch.ethz.seb.sebserver.gbl.model.exam;
 
 import ch.ethz.seb.sebserver.gbl.model.Entity;
 
+/** Overall interface for client group data used either for template or real client groups */
 public interface ClientGroupData extends Entity {
 
     public static final String ATTR_IP_RANGE_START = "ipRangeStart";
     public static final String ATTR_IP_RANGE_END = "ipRangeEnd";
     public static final String ATTR_CLIENT_OS = "clientOS";
 
+    /** All known and implemented client group types */
     public enum ClientGroupType {
         NONE,
         IP_V4_RANGE,
         CLIENT_OS
     }
 
+    /** All known and implemented SEB OS types */
     public enum ClientOS {
         NONE(null),
         WINDOWS("Windows"),
-        MAC_OS("TODO"),
-        I_OS("TODO");
+        MAC_OS("macOS"),
+        I_OS("iOS");
 
         public final String queryString;
 
diff --git a/src/main/java/ch/ethz/seb/sebserver/gui/content/exam/ExamClientGroupList.java b/src/main/java/ch/ethz/seb/sebserver/gui/content/exam/ExamClientGroupList.java
index b9e5553d..998e5006 100644
--- a/src/main/java/ch/ethz/seb/sebserver/gui/content/exam/ExamClientGroupList.java
+++ b/src/main/java/ch/ethz/seb/sebserver/gui/content/exam/ExamClientGroupList.java
@@ -89,8 +89,8 @@ public class ExamClientGroupList implements TemplateComposer {
         final EntityTable<ClientGroup> clientGroupTable =
                 this.pageService
                         .entityTableBuilder(this.restService.getRestCall(GetClientGroupPage.class))
-                        .withRestCallAdapter(builder -> builder.withURIVariable(
-                                API.PARAM_PARENT_MODEL_ID,
+                        .withRestCallAdapter(builder -> builder.withQueryParam(
+                                ClientGroup.FILTER_ATTR_EXAM_ID,
                                 entityKey.modelId))
                         .withEmptyMessage(CLIENT_GROUP_EMPTY_LIST_MESSAGE)
                         .withMarkup()