Editing Roman numerals (section)

===Zero===
As a non-[[positional notation|positional numeral system]], Roman numerals have no "place-keeping" zeros. Furthermore, the system as used by the Romans lacked a numeral for the number [[0 (number)|zero]] itself (that is, what remains after 1 is subtracted from 1). The word {{wikt-lang|la|nulla}} (the [[Latin]] word meaning "none") was used to represent 0, although the earliest attested instances are medieval. For instance [[Dionysius Exiguus]] used {{lang|la|nulla}} alongside Roman numerals in a manuscript from 525 AD.<ref>{{Cite book |title=Bede: The Reckoning of Time |date=2004 |publisher=Liverpool University Press |isbn=0-85323-693-3 |location=Liverpool |translator-last=Wallis |translator-first=Faith |orig-date=725}}</ref><ref>{{Cite book |title=Byrhtferth's Enchiridion |date=1995 |publisher=Early English Text Society |isbn=978-0-19-722416-8 |editor-last=Baker |editor-first=Peter S. |orig-date=1016 |editor-last2=Lapidge |editor-first2=Michael}}</ref> About 725, [[Bede]] or one of his colleagues used the letter {{rn|N}}, the initial of {{lang|la|nulla}} or of {{wikt-lang|la|nihil}} (the Latin word for "nothing") for 0, in a table of [[epacts]], all written in Roman numerals.<ref name="zero">{{Cite book |title=Opera Didascalica |editor-last=Jones |editor-first=C. W. |series=Corpus Christianorum, Series Latina |volume=123C}}</ref>

The use of {{rn|N}} to indicate "none" long survived in the historic [[apothecaries' system]] of measurement: used well into the 20th century to designate quantities in pharmaceutical prescriptions.<ref name="Bachenheimer">{{Cite book |last=Bachenheimer |first=Bonnie S. |title=Manual for Pharmacy Technicians |date=2010 |isbn=978-1-58528-307-1}}</ref>

In later times, the Arabic numeral "0" has been used as a zero to open enumerations with Roman numbers. Examples include the 24-hour [[Shepherd Gate Clock]] from 1852 and [[tarot]] packs such as the 15th-century [[Sola Busca tarot|Sola Busca]] and the 20th century [[Rider-Waite Tarot|Rider–Waite]] packs.