This enumeration is used to set the SoapHeaderAttribute.Direction property. The direction is relative to the receiving method where the attribute is placed. A value of InOut on a web method specifies that the SoapHeader is sent to the method and back to the client with possible modifications.
public enum SoapHeaderDirection { In = 0x00000001, Out = 0x00000002, InOut = 0x00000003, Fault = 0x00000004 }