Cortex-M Debug Connector

Hi,

Segger J-Link 9-pin Cortex-M Adapter has a 10-pin debug connector specified by ARM (Key pin. physically blocked on debug connector.)

Now i have removed the blockade on pin 7 and connect it to the Arduino Due 10-pin connector (referred as JTAG).

But why is there still a the 4-pin (referred as DEBUG) connector?