IIII2IV1

IIII2IV1 is a fictional puzzle token used in discussions of cipher design and mixed numeral notation. It consists of a single string that combines four I characters, the Arabic digit 2, the Roman numeral IV, and the Arabic digit 1. This arrangement is intended to illustrate how different numeral systems can be embedded in a compact identifier and how interpretation depends on context.

The string can be viewed as four components: IIII, 2, IV, and 1. Each component can be assigned different symbolic values depending on the decoding scheme. For example, IIII is often used in clock dials to denote 4, while IV also represents 4 in standard Roman numerals. Interpreting the sequence as numbers yields 4, 2, 4, 1. Mapping those values to letters (A=1, B=2, etc.) gives a possible but non-unique reading such as D-B-D-A. Other schemes might map segments to positions in a word, to frequencies, or to binary patterns.

In puzzle communities, IIII2IV1 is used as a teaching example of how encoding choices and context shape interpretation, rather than as a canonical cryptographic method. It is generally treated as a fictional construct or a didactic device rather than a real-world standard.

See also: roman numerals, puzzle notation, cipher puzzles.