What is the correct romanization of イー?


According to the rules of Hepburn
(<http://www.halcat.com/roomazi/doc/hep3.html>), しいたけ is correctly romanized
as _shiitake_. What is the correct romanization of イー as in シート? Should it be
_shiito_ or _shīto_ or _shi-to_?




Of course it depends what romanization system you use, but generally (e.g.
[Hepburn](http://en.wikipedia.org/wiki/Hepburn_romanization)) one romanizes
double /i/ as _ii_ , e.g. [しいたけ →
_shiitake_](http://en.wikipedia.org/wiki/Hepburn_romanization#I_.2B_I).

However, a vowel lengthened with the 長音 「ー」 (usually in loanwords) is
romanized differently:

  * **Hepburn**  
a macron over the vowel before it, e.g. シート → _shīto_  
(See _Kenkyūsha's New Japanese-English Dictionary_ for modified Hepburn)

  * **Kunrei-shiki**  
a circumflex over the vowel before it, e.g. シート → _sîto_

  * **Wāpuro rōmaji** (or _wa-puro ro-maji_ )  
a hyphen after the vowel, just as is typed, e.g. シート → _si-to_  
_N.B._ In other systems the hyphen may be inserted for readability.

