DefaultDocument Class
SharePoint 2010
Represents a document that will be provisioned automatically for every DocumentManagementDocumentSet object that is based on the associated content type.
Namespace:
Microsoft.Office.DocumentManagement.DocumentSets
Assembly: Microsoft.Office.DocumentManagement (in Microsoft.Office.DocumentManagement.dll)
Maps to the "default content" document in the Document Set Settings page user interface. To access a default document through the object model, use the ContentTypeTemplate property to return the content type template and then the DefaultDocuments property to access the DefaultDocumentCollection object.