HTML Encode the Entry Text

The RadDropDownTree's EnableEntryTextHtmlEncoding property controls whether the text of the entries will be encoded. By default the property's value is set to "false".

ASPNET

<telerik:RadDropDownTree RenderMode="Lightweight" runat="server" ID="RadDropDownTree1"
    EnableEntryTextHtmlEncoding="true"
    Width="300px"
    DataFieldID="ID"
    DefaultMessage="Select ..."
    DataFieldParentID="ParentID"
    DataTextField="Text">
    <DropDownSettings Width="300px" />
</telerik:RadDropDownTree>

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        RadDropDownTree1.DataFieldID = "ID";
        RadDropDownTree1.DataFieldParentID = "ParentID";
        RadDropDownTree1.DataValueField = "ID";
        RadDropDownTree1.DataTextField = "Text";
        RadDropDownTree1.DataSource = GetData();
        RadDropDownTree1.DataBind();
    }

    RadDropDownTree1.SelectedValue = "4";
}

public DataTable GetData()
{
    var table = new DataTable();
    table.Columns.Add("ID");
    table.Columns.Add("ParentID");
    table.Columns.Add("Value");
    table.Columns.Add("Text");

    table.Rows.Add(new String[] { "1", null, "World_Continents", "World Continents" });
    table.Rows.Add(new String[] { "2", null, "World_Oceans", "World Oceans" });

    table.Rows.Add(new String[] { "3", "1", "Asia", "Asia" });
    table.Rows.Add(new String[] { "4", "1", "Africa", "Africa (<strong> test</strong>)" });
    table.Rows.Add(new String[] { "5", "1", "Australia", "Australia" });
    table.Rows.Add(new String[] { "6", "1", "Europe", "Europe" });
    table.Rows.Add(new String[] { "7", "1", "North_America", "North America" });
    table.Rows.Add(new String[] { "8", "1", "South_America", "South America" });

    table.Rows.Add(new String[] { "9", "2", "Arctic_Ocean", "Arctic Ocean" });
    table.Rows.Add(new String[] { "10", "2", "Atlantic_Ocean", "Atlantic Ocean" });
    table.Rows.Add(new String[] { "11", "2", "Indian_Ocean", "Indian Ocean" });
    table.Rows.Add(new String[] { "12", "2", "Pacific_Ocean", "Pacific Ocean" });
    table.Rows.Add(new String[] { "13", "2", "South_Ocean", "SouthOcean" });
    return table;
}

VB.NET

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load

    If Not IsPostBack Then
        RadDropDownTree1.DataFieldID = "ID"
        RadDropDownTree1.DataFieldParentID = "ParentID"
        RadDropDownTree1.DataValueField = "ID"
        RadDropDownTree1.DataTextField = "Text"
        RadDropDownTree1.DataSource = GetData()
        RadDropDownTree1.DataBind()
    End If

    RadDropDownTree1.SelectedValue = "4"
End Sub

Public Function GetData() As DataTable
    Dim table = New DataTable()
    table.Columns.Add("ID")
    table.Columns.Add("ParentID")
    table.Columns.Add("Value")
    table.Columns.Add("Text")

    table.Rows.Add(New [String]() {"1", Nothing, "World_Continents", "World Continents"})
    table.Rows.Add(New [String]() {"2", Nothing, "World_Oceans", "World Oceans"})

    table.Rows.Add(New [String]() {"3", "1", "Asia", "Asia"})
    table.Rows.Add(New [String]() {"4", "1", "Africa", "Africa (<strong> test</strong>)"})
    table.Rows.Add(New [String]() {"5", "1", "Australia", "Australia"})
    table.Rows.Add(New [String]() {"6", "1", "Europe", "Europe"})
    table.Rows.Add(New [String]() {"7", "1", "North_America", "North America"})
    table.Rows.Add(New [String]() {"8", "1", "South_America", "South America"})

    table.Rows.Add(New [String]() {"9", "2", "Arctic_Ocean", "Arctic Ocean"})
    table.Rows.Add(New [String]() {"10", "2", "Atlantic_Ocean", "Atlantic Ocean"})
    table.Rows.Add(New [String]() {"11", "2", "Indian_Ocean", "Indian Ocean"})
    table.Rows.Add(New [String]() {"12", "2", "Pacific_Ocean", "Pacific Ocean"})
    table.Rows.Add(New [String]() {"13", "2", "South_Ocean", "SouthOcean"})
    Return table
End Function