If there is no top overlay ("white ink"), one might ask why there is no pin one marker on the PCB. Saving cents perhaps?
If there was a pin 1 marker, the best PCB pin 1 markers are solid filled triangles, not circles that look like fly vomit or vias. Triangles are superior for a number of reasons. But most engineers use the default fly vomit because they don't know much better or don't care.