\startenvironment ma-cb-language

\mainlanguage[en]

\setuplabeltext
  [en]
  [            document:author=Main author,
               document:design=Design and style,
        document:contributions=Contributions,
         document:translations=Translations,
        document:illustrations=Illustrations,
   document:commanddefinitions=Command definitions,
         document:commandindex=Command index,
         document:subjectindex=Subject index,
             document:contents=Contents,
              document:manuals=Manuals,
            document:magazines=Magazines,
    document:supportandreading=Support and further reading,
       document:furtherreading=Further reading]

\stopenvironment