\showframe

\starttext

\startbuffer
\startlines
first
second
third
fourth

first
second
third
fourth
\stoplines
\stopbuffer

\setupindenting[medium,first]

\setuplines[indenting=no]
\getbuffer


\setuplines[indenting=yes]
\getbuffer

\setuplines[indenting=odd]
\getbuffer

\setuplines[indenting=even]
\getbuffer

\stoptext