In the Unicode Standard v. 5.1, this range has 54 characters, comprising a number of vulgar fractions and Roman numerals. As a rule, we recommend that Roman numerals should be encoded using the ordinary characters I, V, X, L, C and D. The five numerals selected here are combinations of ‘C’ and/or ‘D’ outside the ordinary alphabet, and the reversed ‘C’, which could be used as a Roman numeral as well as an abbreviation sign for ‘con’, and a Claudian letter. Note that two superscript Roman numerals have been added in the Private Use Area, subrange 11 (pp. 136–37 below).