When Roman numerals are used on a clock face, why is the number 4 usually written as IIII rather than IV? Are there any other instances where IIII is used in favour of IV?

Question

When Roman numerals are used on a clock face, why is the number 4 usually written as IIII rather than IV? Are there any other instances where IIII is used in favour of IV?

In: Other

Answer 1

In addition to clocks, there is at least one more use: precision class of commercial scales. There are classes from I (very high precision) to IIII (very rough, higher deviations allowed).

Source: NIST Handbook 44 (unfortunately, not really public as you have to buy it from NIST).