Extension

An extension.

Property Name	Type	Description	Filter Group and Version	Available Version
`alternativeRepresentation`	Alternative	Alternative representation of the extension.	Small, 40.0	40.0
`attachmentId`	String	Attachment ID of the extension.	Small, 41.0	41.0
`extensionId`	String	ID of the extension.	Small, 40.0	40.0
`payload`	String	Payload associated with the extension.	Small, 40.0	40.0
`payloadVersion`	String	Payload version that identifies the structure of the payload associated with the extension.	Small, 40.0	40.0

Connect REST API Developer Guide