A client version vector request uses a value of VERSION_CHANGE_TYPE to indicate whether it is requesting a version chain vector change notification or a full version chain vector.

 typedef  enum 
 {
   CHANGE_NOTIFY = 0,
   CHANGE_ALL = 2
 } VERSION_CHANGE_TYPE;

CHANGE_NOTIFY:  The client requests notification only for a change of the server’s version chain vector.

CHANGE_ALL:  The client requests to receive the full version vector of the server.