Index: Core/Components/src/Core.Components.PointedTree/Core.Components.PointedTree.csproj
===================================================================
diff -u -reb0b935ed63fa3d09a438c897044f95e645c95b9 -r40514f2e47eded8cd37dad8d7e17829e77565d92
--- Core/Components/src/Core.Components.PointedTree/Core.Components.PointedTree.csproj	(.../Core.Components.PointedTree.csproj)	(revision eb0b935ed63fa3d09a438c897044f95e645c95b9)
+++ Core/Components/src/Core.Components.PointedTree/Core.Components.PointedTree.csproj	(.../Core.Components.PointedTree.csproj)	(revision 40514f2e47eded8cd37dad8d7e17829e77565d92)
@@ -37,6 +37,8 @@
     <Reference Include="System" />
     <Reference Include="System.Core" />
     <Reference Include="System.Drawing" />
+    <Reference Include="System.Xml" />
+    <Reference Include="System.Xml.Linq" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="..\..\..\Common\src\Core.Common.Version\GlobalAssembly.cs">
Index: Core/Components/src/Core.Components.PointedTree/Data/GraphNode.cs
===================================================================
diff -u -r3e86aa56a8e99291f35ffe7b88df33e90d6d68c9 -r40514f2e47eded8cd37dad8d7e17829e77565d92
--- Core/Components/src/Core.Components.PointedTree/Data/GraphNode.cs	(.../GraphNode.cs)	(revision 3e86aa56a8e99291f35ffe7b88df33e90d6d68c9)
+++ Core/Components/src/Core.Components.PointedTree/Data/GraphNode.cs	(.../GraphNode.cs)	(revision 40514f2e47eded8cd37dad8d7e17829e77565d92)
@@ -22,6 +22,11 @@
 using System;
 using System.Collections.Generic;
 using System.Drawing;
+using System.IO;
+using System.Xml;
+using System.Xml.Linq;
+using System.Xml.Schema;
+using Core.Components.PointedTree.Properties;
 
 namespace Core.Components.PointedTree.Data
 {
@@ -40,8 +45,14 @@
         /// <param name="isSelectable">Indicator whether the node is selectable.</param>
         /// <exception cref="ArgumentNullException">Thrown when <paramref name="content"/>
         /// or <paramref name="childNodes"/> is <c>null</c>.</exception>
+        /// <exception cref="ArgumentException">Thrown when the content is not valid.</exception>
+        /// <remarks>Content should have the following format: &lt;text&gt;Content&lt;/text&gt;.
+        /// The following tags are supported as content:
+        /// <list type="bullet">
+        /// <item>&lt;bold&gt;&lt;/bold&gt;</item>
+        /// </list></remarks>
         public GraphNode(string content, GraphNode[] childNodes, bool isSelectable)
-            : this(content, childNodes, isSelectable, CreateDefaultGraphNodeStyle()) { }
+            : this(content, childNodes, isSelectable, CreateDefaultGraphNodeStyle()) {}
 
         /// <summary>
         /// Creates a new instance of <see cref="GraphNode"/>.
@@ -52,6 +63,12 @@
         /// <param name="style">The style of the node.</param>
         /// <exception cref="ArgumentNullException">Thrown when <paramref name="content"/>,
         /// <paramref name="childNodes"/> or <paramref name="style"/> is <c>null</c>.</exception>
+        /// <exception cref="ArgumentException">Thrown when the content is not valid.</exception>
+        /// <remarks>Content should have the following format: &lt;text&gt;Content&lt;/text&gt;.
+        /// The following tags are supported as content:
+        /// <list type="bullet">
+        /// <item>&lt;bold&gt;&lt;/bold&gt;</item>
+        /// </list></remarks>
         public GraphNode(string content, GraphNode[] childNodes, bool isSelectable, GraphNodeStyle style)
         {
             if (content == null)
@@ -67,6 +84,8 @@
                 throw new ArgumentNullException(nameof(style));
             }
 
+            ValidateContent(content);
+
             Content = content;
             this.childNodes = childNodes;
             IsSelectable = isSelectable;
@@ -99,6 +118,29 @@
         /// </summary>
         public GraphNodeStyle Style { get; }
 
+        /// <summary>
+        /// Validates whether the content is valid XML.
+        /// </summary>
+        /// <param name="content">The content to validate.</param>
+        /// <exception cref="ArgumentException">Thrown when the
+        /// content is not valid.</exception>
+        private static void ValidateContent(string content)
+        {
+            var xmlSchemaSet = new XmlSchemaSet();
+            xmlSchemaSet.Add(XmlSchema.Read(new StringReader(Resources.GraphNodeContentSchema), null));
+            xmlSchemaSet.Compile();
+
+            try
+            {
+                XDocument doc = XDocument.Parse(content);
+                doc.Validate(xmlSchemaSet, null);
+            }
+            catch (Exception e) when (e is XmlException || e is XmlSchemaValidationException)
+            {
+                throw new ArgumentException(Resources.GraphNode_ValidateContent_Content_not_valid, e);
+            }
+        }
+
         private static GraphNodeStyle CreateDefaultGraphNodeStyle()
         {
             return new GraphNodeStyle(GraphNodeShape.Rectangle, Color.Gray, Color.Black, 2);
Index: Core/Components/src/Core.Components.PointedTree/Properties/Resources.Designer.cs
===================================================================
diff -u -reb0b935ed63fa3d09a438c897044f95e645c95b9 -r40514f2e47eded8cd37dad8d7e17829e77565d92
--- Core/Components/src/Core.Components.PointedTree/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision eb0b935ed63fa3d09a438c897044f95e645c95b9)
+++ Core/Components/src/Core.Components.PointedTree/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 40514f2e47eded8cd37dad8d7e17829e77565d92)
@@ -82,11 +82,28 @@
         }
         
         /// <summary>
-        ///   Looks up a localized string similar to &lt;xs:schema xmlns:xs=&quot;http://www.w3.org/2001/XMLSchema&quot;&gt;
-        ///	&lt;xs:element name=&quot;text&gt;
+        ///   Looks up a localized string similar to De content voor deze node is niet geldig..
+        /// </summary>
+        internal static string GraphNode_ValidateContent_Content_not_valid {
+            get {
+                return ResourceManager.GetString("GraphNode_ValidateContent_Content_not_valid", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to &lt;!--
+        ///Copyright (C) Stichting Deltares 2017. All rights reserved.
         ///
-        ///	&lt;/xs:element&gt;
-        ///&lt;/xs:schema&gt;.
+        ///This file is part of Ringtoets.
+        ///
+        ///Ringtoets is free software: you can redistribute it and/or modify
+        ///it under the terms of the GNU Lesser General Public License as published by
+        ///the Free Software Foundation, either version 3 of the License, or
+        ///(at your option) any later version.
+        ///
+        ///This program is distributed in the hope that it will be useful,
+        ///but WITHOUT ANY WARRANTY; without even the implied warranty of
+        ///MERCHANTABILITY or FITNESS FO [rest of string was truncated]&quot;;.
         /// </summary>
         internal static string GraphNodeContentSchema {
             get {
Index: Core/Components/src/Core.Components.PointedTree/Properties/Resources.resx
===================================================================
diff -u -reb0b935ed63fa3d09a438c897044f95e645c95b9 -r40514f2e47eded8cd37dad8d7e17829e77565d92
--- Core/Components/src/Core.Components.PointedTree/Properties/Resources.resx	(.../Resources.resx)	(revision eb0b935ed63fa3d09a438c897044f95e645c95b9)
+++ Core/Components/src/Core.Components.PointedTree/Properties/Resources.resx	(.../Resources.resx)	(revision 40514f2e47eded8cd37dad8d7e17829e77565d92)
@@ -121,4 +121,7 @@
   <data name="GraphNodeContentSchema" type="System.Resources.ResXFileRef, System.Windows.Forms">
     <value>..\Resources\GraphNodeContentSchema.xsd;System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089;Windows-1252</value>
   </data>
+  <data name="GraphNode_ValidateContent_Content_not_valid" xml:space="preserve">
+    <value>De content voor deze node is niet geldig.</value>
+  </data>
 </root>
\ No newline at end of file
Index: Core/Components/test/Core.Components.GraphSharp.Forms.Test/PointedTreeGraphControlTest.cs
===================================================================
diff -u -r1fb18822ebf5a2e3dae6eb2dc3c4687e4d1d0e62 -r40514f2e47eded8cd37dad8d7e17829e77565d92
--- Core/Components/test/Core.Components.GraphSharp.Forms.Test/PointedTreeGraphControlTest.cs	(.../PointedTreeGraphControlTest.cs)	(revision 1fb18822ebf5a2e3dae6eb2dc3c4687e4d1d0e62)
+++ Core/Components/test/Core.Components.GraphSharp.Forms.Test/PointedTreeGraphControlTest.cs	(.../PointedTreeGraphControlTest.cs)	(revision 40514f2e47eded8cd37dad8d7e17829e77565d92)
@@ -69,14 +69,14 @@
             // Given
             using (var graphControl = new PointedTreeGraphControl())
             {
-                var doubleUsedNode = new GraphNode("Double used", new GraphNode[0], false);
-                var node = new GraphNode("Root", new[]
+                var doubleUsedNode = new GraphNode("<text>Double used</text>", new GraphNode[0], false);
+                var node = new GraphNode("<text>Root</text>", new[]
                 {
-                    new GraphNode("Child 1", new[]
+                    new GraphNode("<text>Child 1</text>", new[]
                     {
                         doubleUsedNode
                     }, false),
-                    new GraphNode("Child 2", new[]
+                    new GraphNode("<text>Child 2</text>", new[]
                     {
                         doubleUsedNode
                     }, false)
@@ -100,9 +100,9 @@
         public void GivenGraphControlWithData_WhenDataSetToOtherGraphNode_ThenGraphControlUpdated()
         {
             // Given
-            var node = new GraphNode("Root", new[]
+            var node = new GraphNode("<text>Root</text>", new[]
             {
-                new GraphNode("Child 1", new GraphNode[0], false)
+                new GraphNode("<text>Child 1</text>", new GraphNode[0], false)
             }, false);
 
             using (var graphControl = new PointedTreeGraphControl
@@ -120,7 +120,7 @@
                 Assert.AreEqual(1, graph.EdgeCount);
 
                 // When
-                graphControl.Data = new GraphNode("Double used", new GraphNode[0], false);
+                graphControl.Data = new GraphNode("<text>Double used</text>", new GraphNode[0], false);
 
                 // Then
                 Assert.AreEqual(1, graph.VertexCount);
@@ -132,9 +132,9 @@
         public void GivenGraphControlWithData_WhenDataSetToNull_ThenGraphControlUpdated()
         {
             // Given
-            var node = new GraphNode("Root", new[]
+            var node = new GraphNode("<text>Root</text>", new[]
             {
-                new GraphNode("Child 1", new GraphNode[0], false)
+                new GraphNode("<text>Child 1</text>", new GraphNode[0], false)
             }, false);
 
             using (var graphControl = new PointedTreeGraphControl
Index: Core/Components/test/Core.Components.GraphSharp.Test/Converters/GraphNodeConverterTest.cs
===================================================================
diff -u -r1fb18822ebf5a2e3dae6eb2dc3c4687e4d1d0e62 -r40514f2e47eded8cd37dad8d7e17829e77565d92
--- Core/Components/test/Core.Components.GraphSharp.Test/Converters/GraphNodeConverterTest.cs	(.../GraphNodeConverterTest.cs)	(revision 1fb18822ebf5a2e3dae6eb2dc3c4687e4d1d0e62)
+++ Core/Components/test/Core.Components.GraphSharp.Test/Converters/GraphNodeConverterTest.cs	(.../GraphNodeConverterTest.cs)	(revision 40514f2e47eded8cd37dad8d7e17829e77565d92)
@@ -50,7 +50,7 @@
         public void Convert_InvalidShapeType_ThrowsInvalidEnumArgumentException()
         {
             // Setup
-            var graphNode = new GraphNode("test", new GraphNode[0], false,
+            var graphNode = new GraphNode("<text>test</text>", new GraphNode[0], false,
                                           new GraphNodeStyle((GraphNodeShape) 99, Color.AliceBlue,
                                                              Color.AntiqueWhite, 2));
 
@@ -69,7 +69,7 @@
                                                                          PointedTreeVertexType expectedVertexType)
         {
             // Setup
-            const string content = "Node";
+            const string content = "<text>Node</text>";
             const bool isSelectable = false;
             const int lineWidth = 3;
             Color fillColor = Color.Aquamarine;
Index: Core/Components/test/Core.Components.PointedTree.Test/Core.Components.PointedTree.Test.csproj
===================================================================
diff -u -r2a9569e9a7d82f4f1627fc6eaafd9bda61ac0feb -r40514f2e47eded8cd37dad8d7e17829e77565d92
--- Core/Components/test/Core.Components.PointedTree.Test/Core.Components.PointedTree.Test.csproj	(.../Core.Components.PointedTree.Test.csproj)	(revision 2a9569e9a7d82f4f1627fc6eaafd9bda61ac0feb)
+++ Core/Components/test/Core.Components.PointedTree.Test/Core.Components.PointedTree.Test.csproj	(.../Core.Components.PointedTree.Test.csproj)	(revision 40514f2e47eded8cd37dad8d7e17829e77565d92)
@@ -62,6 +62,10 @@
     <None Include="packages.config" />
   </ItemGroup>
   <ItemGroup>
+    <ProjectReference Include="..\..\..\Common\test\Core.Common.TestUtil\Core.Common.TestUtil.csproj">
+      <Project>{D749EE4C-CE50-4C17-BF01-9A953028C126}</Project>
+      <Name>Core.Common.TestUtil</Name>
+    </ProjectReference>
     <ProjectReference Include="..\..\src\Core.Components.PointedTree\Core.Components.PointedTree.csproj">
       <Project>{ad3b1634-c435-4618-9971-2ea0817f5de2}</Project>
       <Name>Core.Components.PointedTree</Name>
Index: Core/Components/test/Core.Components.PointedTree.Test/Data/GraphNodeTest.cs
===================================================================
diff -u -r3e86aa56a8e99291f35ffe7b88df33e90d6d68c9 -r40514f2e47eded8cd37dad8d7e17829e77565d92
--- Core/Components/test/Core.Components.PointedTree.Test/Data/GraphNodeTest.cs	(.../GraphNodeTest.cs)	(revision 3e86aa56a8e99291f35ffe7b88df33e90d6d68c9)
+++ Core/Components/test/Core.Components.PointedTree.Test/Data/GraphNodeTest.cs	(.../GraphNodeTest.cs)	(revision 40514f2e47eded8cd37dad8d7e17829e77565d92)
@@ -23,6 +23,7 @@
 using System.Collections.Generic;
 using System.Drawing;
 using System.Linq;
+using Core.Common.TestUtil;
 using Core.Components.PointedTree.Data;
 using NUnit.Framework;
 
@@ -44,14 +45,14 @@
 
             GraphNode[] childNodes =
             {
-                new GraphNode("node 1", new GraphNode[0], false, style),
-                new GraphNode("node 2", new[]
+                new GraphNode("<text>node 1</text>", new GraphNode[0], false, style),
+                new GraphNode("<text>node 2</text>", new[]
                 {
-                    new GraphNode("node 3", new GraphNode[0], false, style)
+                    new GraphNode("<text>node 3</text>", new GraphNode[0], false, style)
                 }, true, style)
             };
 
-            const string content = "test";
+            const string content = "<text>test</text>";
             const bool isSelectable = false;
 
             // Call
@@ -72,14 +73,14 @@
             // Setup
             GraphNode[] childNodes =
             {
-                new GraphNode("node 1", new GraphNode[0], false),
-                new GraphNode("node 2", new[]
+                new GraphNode("<text>node 1</text>", new GraphNode[0], false),
+                new GraphNode("<text>node 2</text>", new[]
                 {
-                    new GraphNode("node 3", new GraphNode[0], true)
+                    new GraphNode("<text>node 3</text>", new GraphNode[0], true)
                 }, true)
             };
 
-            const string content = "test";
+            const string content = "<text>test</text>";
             const bool isSelectable = false;
 
             // Call
@@ -112,7 +113,7 @@
         public void Constructor_ChildNodesNull_ThrowsArgumentNullException()
         {
             // Call
-            TestDelegate call = () => new GraphNode("test", null, false);
+            TestDelegate call = () => new GraphNode("<text>test</text>", null, false);
 
             // Assert
             var exception = Assert.Throws<ArgumentNullException>(call);
@@ -123,13 +124,26 @@
         public void Constructor_StyleNull_ThrowsArgumentNullException()
         {
             // Call
-            TestDelegate call = () => new GraphNode("test", new GraphNode[0], false, null);
+            TestDelegate call = () => new GraphNode("<text>test</text>", new GraphNode[0], false, null);
 
             // Assert
             var exception = Assert.Throws<ArgumentNullException>(call);
             Assert.AreEqual("style", exception.ParamName);
         }
 
+        [Test]
+        [TestCase("plain text")]
+        [TestCase("<text>test")]
+        [TestCase("<text>test <italic>italic</italic></text>")]
+        public void Constructor_InvalidContent_ThrowsArgumentException(string content)
+        {
+            // Call
+            TestDelegate call = () => new GraphNode(content, new GraphNode[0], false);
+
+            // Assert
+            TestHelper.AssertThrowsArgumentExceptionAndTestMessage<ArgumentException>(call, "De content voor deze node is niet geldig.");
+        }
+
         private static void AssertChildNodes(IList<GraphNode> childNodes, IList<GraphNode> actualChildNodes)
         {
             Assert.AreEqual(childNodes.Count, actualChildNodes.Count);