This is a discussion on an edited compendium of various theories, primarily postings to the Clocks Mailing List and to the alt.horology newsgroup in 1995-6 concerning why the Roman IIII is used instead of IV on clock dials.
Click on link to read: http://www.ubr.com/clocks/frequently-asked-questions-faq/faq-roman-iiii-vs-iv-on-clock-dials.aspx