In every CSV file generated by iNaturalist, insert this at the first line:
Don’t put anything else on this first line. The CSV file opened in a text editor should show as follows:
This indicates to the sofware that opens the document (e.g. MS Excel) that a comma is used as the column separator.
It is important because in French we use the comma, not the dot, as the decimal “point”, for writing floating “point” numbers (in French we say: floating comma numbers). This implied (I guess) that a semicolon was adopted as the default column separator in CSV files in France. As a consequence, a CSV file not using the semicolon as the default column separator will not be opened correctly by a French edition of MS Excel. Fortunately there is a way to specify within the CSV file (basically a text file) another separator than the default one.
Adding this extra line in the CSV file will NOT impact non-French editions of MS Excel.