Note 1: (*) These numbers were written either with an overline (a bar above the number) or between two vertical lines (two vertical bars).
Note 2 (*) Instead we prefer to write these larger numerals between brackets "()" since: 1) when compared to the overline - it is more accessible to computer users; 2) when compared to the vertical line - it avoids any confusion between the vertical line "|" and the Roman numeral "I" (one).
Note 3: (*) Romans were not using right from the beginning numbers larger than 3,999, so they initially had no representation for numbers like:
These larger numerals were added later to the system and various different notations were used for them, not necessarily the ones above.
For a long time, the maximum number that could be written using Roman numerals was: