Are you referring to these properties on the SOAP object
AutoAddSubscribers xsd:boolean Indicates whether a triggered send recipient is added to a subscriber list. If set to True, the call automatically adds the email address associated with the triggered send to a specified subscriber list.
AutoUpdateSubscribers xsd:boolean Indicates if any subscriber information is updated as part of a triggered send. If set to True, the triggered send call updates any applicable subscriber information with information from the send.