Over here in the UK we call those die polishing marks. The dies are polished up, sometimes leaving small scratches, prior to the design being imprinted and the die hardened.
Remember dies are negatives, so a scratch on a die leaves a raised line on the coin itself. You can tell the difference between die polishing marks and scratches on the coin because the die marks will run under / through the design.
Heres a (very old) coin of mine. You can see behind the King' head similar lines that run under the crown.

Edited by Tom Goodheart
04/02/2014 11:38 am