Hi Hans, the following example fails with named parameters, is this a limitation of mkvi? % macros=mkvi \def\definefoo[#1]% {\setvalue{start#1}{\dostartfoo{#1}}} \def\dostartfoo#1% {\normalexpanded{\def\noexpand\next##1\expandafter\noexpand\csname stop#1\endcsname}{#1 : ##1}% \next} %\def\definefoo[#name]% % {\setvalue{start#name}{\dostartfoo{#name}}} % %\def\dostartfoo#name% % {\normalexpanded{\def\noexpand\next#content\expandafter\noexpand\csname stop#name\endcsname}{#name : #content}% % \next} \starttext \definefoo[foo] \startfoo bar\stopfoo \stoptext Wolfgang