Command/startlocalnotes

\definenote[testnote]
% add a bit of visual contrast:
\setupnote
  [testnote]
  [textstyle=boldface]
\setupnotation
   [testnote]
   [numberconversion=romannumerals] %

\starttext
Some text.\testnote{First testnote, not \quote{local}.}
And some more.\footnote{This is a normal footnote.}

\startlocalnotes[testnote]
\input knuth \testnote{Donald dixit}
Foo\testnote{Nonsens.} bar baz\footnote{This is also a normal footnote.}

\framed[width=\textwidth,align=flushleft]{\placelocalnotes[testnote]}
\stoplocalnotes

The End.
\stoptext