There are two cases: 1. You want Introduction in the table of contents. Then you should copy section to another head, and setup it with number=no (have no time to test):

\definehead[secnonum][section] \setuphead[secnonum][number=no] \secnonum{Introduction}

2. You don't want Intruduction in the table of contents. Then just use \subject{Introduction}.

Thank you too! I do want Introduction to be in the contents! Maybe, its easier to setup \subject so that it will be included, then to invent new keywords? -- Best Regards, Vyatcheslav Yatskovsky