AXIOMTEK MANO310 Series User Manual page 14

MANO310 Mini ITX Motherboard
To identify the first pin of a header or jumper, please refer to the following
information:

Usually, there is a thick line or a triangle near the header or jumper pin 1.
Note

Square pad, which you can find on the back of the motherboard, is usually
used for pin 1.
8 Board and Pin Assignments