This is the STMicroelectronics STDC14 standard JTAG/SWD debug cable.
Pins 3-12 are exactly the same as the standard ARM Cortex 10pin connector. This enables this cable to be connected to the 10pin header by overhanding the outer pins beyond the connector. This is possible on boards that either use a free standing pin header or use the Samtec FTSH Keyed connectors.
In the STDC14 standard the outer pins 1-2 are reserved, and pins 13-14 are used for UART.