Front rail punchings on tuning pins

[Kristinn Leifsson]

Hi guys and gals,

I just tuned an old Hindsberg with relatively new strings.
Someone had put front rail punchings on the tuning pin for the left string 
of every A.
I´ve seen this before, and thought maybe, on some occasions this was left 
over from some old tech that wanted to mark excessively loose pin, or 
something.  There was, however, nothing wrong with the torque of any of these.
But why on all the A´s?

Best regards,

Kristinn Leifsson,
Reykjavík, Iceland