WCF excluding datamembers to be serialized in the Derived class
[DataContract]
public class Base
{
  [DataMember]
  public virtual string Name
  {get; set; }
}
[DataContract]
public class Derived: Base
{
   [IgnoreDataMember]
   public override string Name
   {get; set; }
}

public class Base
{
    [XmlIgnore]
    public virtual  string Name { get; set; }
}

public class Derived : Base
{
    [XmlIgnore] //Remove this to include
    public override string Name { get; set; }
}
MemoryStream memStream = new MemoryStream();
XmlSerializer xmlSer = new XmlSerializer(typeof(Derived));
xmlSer.Serialize(memStream, new Derived() { Name = "aaaa" });
MessageBox.Show(Encoding.UTF8.GetString(memStream.ToArray()));