All the BV3's have a connector at the back. But it isn't really a connector on the back, but on the chassis itself.
On the back there is a retangular hole where the motor stand cable via a adapter/converter/connector goes through .
Basically, that rectangular connector has also the same 5 pins as the round version.
So, there exists an adapter which goes from 5 pins round to 5 pins rectangular.
If you have the stand connected, then the option STAND will be available.
Bear in mind, that the newer motor plate from a 88xx doesn't fit on a 8800 version.