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MustUnderstandBehavior Class

Instructs Windows Communication Foundation (WCF) to disable the mandatory processing of headers not in the UnderstoodHeaders collection that must be understood according to the SOAP 1.1 and 1.2 specifications.

Namespace:  System.ServiceModel.Description
Assembly:  System.ServiceModel (in System.ServiceModel.dll)

public class MustUnderstandBehavior : IEndpointBehavior

By default the WCF client or service runtime throws an exception when it encounters a System.ServiceModel.Channels.MessageHeader in a message for which the MessageHeader.MustUnderstand property is true but the header is not in the MessageHeaders.UnderstoodHeaders property for the message.

To prevent this behavior, use the MustUnderstandBehavior and set the ValidateMustUnderstand property to false. Typically, this is used in scenarios where the message content is meant to be relayed somewhere else and not processed, such as a router service.


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0