It is a hard job to understand how all works ... I tried to create the first example of the documentation "Page 257 Anchors and layers", but failed with mkii and iv. The page is created, but without the graphical elements. Not using \startbuffer--\stopbuffer makes no difference.
MTXrun | current version: 2010.07.30 11:35
Herbert
\starttext
\section {Anchors and layers}
\startbuffer[a] \setMPpositiongraphic{X-1}{mypos:arrow}{to=X-2} \setMPpositiongraphic{X-2}{mypos:arrow}{to=X-3} \stopbuffer
\startbuffer[b] In a previous section we saw that some \hpos {X-1} {words} were \hpos {X-2} {circled} and connected by an \hpos {X-3} {arrow}. As with most things in \CONTEXT, marking these words is separated from declaring what to do with those words. This paragraph is keyed in as: \stopbuffer
\getbuffer[a,b]
\stoptext