*''Nn'' for ん (Hepburn ''n''). This is also an example of ''wāpuro rōmaji'' (although many [[Japanese input methods]] also accept the Hepburn ''<nowiki>n'</nowiki>''). This leads to ambiguity with the more widespread Hepburn system. For example, the cluster ''nna'', which is んな in Hepburn, represents んあ in this system. The double n is sometimes seen in names, for example in the name of the well-known [[Usenet]] poster ''Junn Ohta''.
The most common variant romanization is to omit the macrons or circumflexes used to indicate a long vowel. This is extremely common in the romanized version of Japanese words used in English. For example the capital city of Japan, correctly written Tōkyō in romanized Japanese, is universally written as Tokyo. In Japan, since romanized Japanese is seen mostly as a convenience for foreigners to be able to read signs easily, macrons and circumflexes are usually omitted for simplification.
Many [[typewriter]]s, [[word processor]]s, and computerized systems cannot easily deal with the macron used in Hepburn romanization. Nihon-shiki and Kunrei-shiki use a [[circumflex]] accent (thus, Tôkyô). This may allow for easier input, since all of â, î, û, ê, and ô are in the [[ISO-8859-1]] character set, and may be easily input on a variety of systems.