No, there is no missed rule, the comma is the only official decimal separator in these parts.
But I can relate to the the OP.
Us here in the comma world are forever converting numbers in CSV and Excel files back and forth so as to display them in a proper number format.
It’s like that darned USB port, you have to flip it 3 times to get it right.
Since it's a big "moat" for parts manufacturing (mainly for defense industry)... I predict the USA will give up imperial units when it's empire finally collapses.
Perhaps in the next few decades as China builds its own economic sphere.
We also use apostrophe as the thousands separator, so: 1'234'567.89 which I personally always found much more readable that using commas and dots. Is there any other country that uses this combination?
While OP here made a mistake, some countries use mixed systems depending on what it is used for . Switzerland for example uses comma for normal numbers and dot for currency alone.
