I think in that file 62 is sanguinololu and then melzi is 63 instead.
The uC has a pin numbering scheme. If you open the pcb source (the source file in which the pcb was made), that will show basically your entire board and you can see which pin is used in a certain way. Those pin numbers are then put into the pins.h file, so the firmware knows what each pin is supposed to do. For example between sanguinololu and melzi many pins coincide, but still some are different because who made the board optimized things in its own way. At least thats the logic behind it. To make things confusing, normal arduino boards have pins with numbering which do not necessarily coincide with the uC pin numbering, and on top of that there is some analog and then some digital numbering. It doesnt matter much and normally boards pins.h are already correct in firmware, but just be aware what they mean and what wrong pinout reference definition can do.
The uC has a pin numbering scheme. If you open the pcb source (the source file in which the pcb was made), that will show basically your entire board and you can see which pin is used in a certain way. Those pin numbers are then put into the pins.h file, so the firmware knows what each pin is supposed to do. For example between sanguinololu and melzi many pins coincide, but still some are different because who made the board optimized things in its own way. At least thats the logic behind it. To make things confusing, normal arduino boards have pins with numbering which do not necessarily coincide with the uC pin numbering, and on top of that there is some analog and then some digital numbering. It doesnt matter much and normally boards pins.h are already correct in firmware, but just be aware what they mean and what wrong pinout reference definition can do.