Hello,

In the example below...

----------------------------------------------------

%\def\myCommand#1#2{}
\def\myCommand#1#2{#1 #2}
%\def\myCommand{}

\setuphead[chapter]
    [number=yes,
     align=middle,
%  anyotherparameter=whatever,
    command=\myCommand]
%    command=]
     
\starttext

\startfrontmatter
    %\placecontent
    \completecontent
\stopfrontmatter

\startbodymatter   
    \chapter{chapter one}

    \dorecurse{5}{\input tufte\par}

    \chapter{chapter two}

    \dorecurse{5}{\input douglas\par}
\stopbodymatter

\stoptext

----------------------------------------------------

... how do you define myCommand so

\setuphead[chapter]
    [(any other parameter settings),
    command=\myCommand,
    (any other parameter settings)]

is equal to

\setuphead[chapter]
    [(any other parameter settings),
    command=,
    (any other parameter settings)]

i.e. with any other parameter settings remaining active.

In the example above, with align=middle and

- \def\myCommand#1#2{} the ToC and chapter heads are blank
- \def\myCommand#1#2{#1 #2} the ToC and chapter head alignment is lost
- \def\myCommand{} the ToC and chapter head alignment is lost


Thanks,
Alan