System.CodeDom.CodeBaseReferenceExpression represents a reference to the base class of the current class. The base class is sometimes also known as the parent class or super class. References to the base class are commonly used when overriding a method or property in order to call the base class's implementation of that method or property. For example, an override of a ToString method that appends a string to the end of the base class's ToString method would call base.ToString() in C#.