In #openbsd what is called #vi is actually #nvi, and when you install #nvi from ports, it is #nvi2.
To danes with our national characters æøå we need the latter because #vi prints two byte hex sequences for æ, ø, or å. #vi handles them correctly except for the printing of them.
#vi and #nvi use the same #man page.

Update:
On #netbsd #vi is also #nvi. Here you must install #nvi2 to get #nvi if you need æ, ø, and å support.

Best wishes from T. R. Dane (The Real Dane ;)