Decimal separator in woodstock series displays

[aurelio]

Hello, I would like to know some more about the comma in the woodstocks' displays. My first HP calculator was a HP25c made in Singapore (76), bought in Italy in the 1977, with a "dot" decimal point. Other two calculators HP29c (79) and a second HP25c (78), both made in Singapore which I bought several years later also have the "dot" decimal separator. A fourth calculator, made in USA, a HP21 (75), shows instead the comma as decimal separator. If I'm not wrong comma is more a european "feature", maybe reserved for the overseas market, so for me unexpected to see in my oldest woodstock, the only one made in USA...
This actually is one of a few HP "red dot" calculator I have seen with a comma in place of the dot, togheter with a couple of spices