Arduino PRO Mini - The pads [was "jumpers"] on the back and Low Power Consumption
Both responses are correct but be mindful that this is a SparkFun feature.  An Arduino Pro Mini from China won't necessarily have the SJ1 pad.

1) Like Gerben said, the pads on the underside of the board are for I2C pull-up resistors.

2) Like David said, SJ1 is on the top of the board next to the GND and RST pins.  (It looks like a small solder blob.)

3) To isolate the regulator from VCC, remove the solder blob on the top of the board with a sucker or solder wick.

The Sparkfun schematic shows all of these elements:
https://cdn.sparkfun.com/datasheets/Dev/Arduino/Boards/Arduino-Pro-Mini-v14.pdf