Datasheet

Stacking headers are installed from the top of the board instead of the bottom, so the
procedure is a little different than for installing simple male headers.
Position the headers:
Insert the headers from the top of the shield, then flip the shield over and place it on a
flat surface. Straighten the headers so that they are vertical.
Be sure to insert the headers from the TOP of the shield so that they can be soldered from
the BOTTOM.
© Adafruit Industries https://learn.adafruit.com/adafruit-data-logger-shield Page 13 of 85