Confused by the Pro Mini pin labeling

I have a couple 3.3V/8MHz Pro Minis in hand and am starting out with them. On the schematic, pin 17 of the AT328 is connected to onboard LED. That same pin goes to JP6, pin 9, and has the net label SCK. Here is where the confusing part comes in: If you run the standard example sketch “blinkled”, the bog-standard code calls for pin 13…and it works! Changing the pin declaration to pin 17 doesn’t.

And if you look at the silkscreen on the board, sure enough, JP6 pin 9 has the label “13”. So it seems I should rely on the silkscreen for the board, not the schematic when designing circuits around the Pro Mini…is this really the case? And could the schematic be updated to reflect this so as to not confuse the poor newb?

Thanks!