Raspberry Pi Zero – Pad probing

The pads on the reverse of the Raspberry Pi Zero look interesting to me.

Raspberry Pi Zero - SD Breakout / Test Pads

So far I’ve checked where these pads are connected.

PP Description
PP1 USB +5V Input
PP6 GND
PP8 3.3V
PP14 SD CLK
PP15 SD CMD
PP16 SD DAT0
PP17 SD DAT1
PP18 SD DAT2
PP19 SD CD
PP22 USB D+
PP23 USB D-