Alan BRASLAU
17. Januar 2016 um 23:39
On Sun, 17 Jan 2016 20:09:56 +0100

Thanks, again, these are useful pointers.
In conclusion, good practice could be (but would this work?):

\startdocument
[title=My title,
metadata:title=\documentvariable{title},
author=Me,
metadata:author=\documentvariable{author}]
...
\stopdocument
I would separate both settings and put \setupdocument somewhere in the preamble.

\setupdocument
  [metadata:title=\documentvariable{title},
   metadata:author=\documentvariable{author}]

\startdocument
  [title=My title,
   author=Me]
...
\stopdocument

Wolfgang