About writing of Chinese coins

Jan, 15, 1999
A question from Ph. GRAULICH, member of the Numismatic club of Liège (Belgium) and European Numismatic Alliance:

       Some authors says that the presence of different sorts of characters (seal, clerkly, running hand, ...) in the same series of coins is a monetary mark to distinguish the different productions or mints. But I read now that we can determinate the precise year of coins (from Kuang-Hsu i.e.) with the difference between calligraphy of the same characters.

       Do you have an answer about these two points?