In France, the full stop was already in use in printing to make Roman numerals more readable, so the comma was chosen.[14] Many other countries, such as Italy, also chose to use the comma to mark the decimal units position.[14] It has been made standard by the ISO for international blueprints.[15] However, English-speaking countries took the comma to separate sequences of three digits. In some countries, a raised dot or dash (upper comma) may be used for grouping or decimal separator; this is particularly common in handwriting.