On 15 Jan 2014, at 21:54 , Wolfgang Schuster <schuster.wolfgang@gmail.com>
 wrote:

> Am 15.01.2014 um 15:36 schrieb Robert Blackstone <blackstone.robert@gmail.com>:
> 
>> Dear all, 
>> 
>> Is there, in a book-project, a way to place unnumbered chapters, in casu Acknowledgements and Abstract, in the FrontMatter before the ToC, but still mentioned in the ToC?
> 
> \definehead[prechapter][chapter]
> \setuphead [prechapter][number=no,incrementnumber=list]
> 
> \starttext
> 
> \prechapter{Unnumbered chapter}
> 
> \title{Contents}
> 
> \placelist[prechapter,chapter]
> 
> \chapter{Numbered chapter}
> 
> \stoptext
> 
> Wolfgang

Thank you Wolfgang. This works and it will very likely also work for my project. 
I'm afrraid though that I left out an important detail, namely that the ToC itself must be mentioned in the ToC.
What I'm expected to emulate is the following: (with real pagenumbers of course)

CONTENTS

Acknowledgements				i
Abstract							ii
Contents						iii
List of Illusttratiions				iv
List of Tables					v
Abbreviations and Library sigla	vi
Preface							vii

Chapter 1						8
Chapter 2 etc.

So my real question should have been: Is there a way to place the ToC in an unnumbered chapter, which should not be at the very beginning of the book? 
But you have suggested the answer already: Changing \title{Contents} to \prechapter{Contents} does just that. Clean solution for an, imho,  odd request.

Best regards,
Robert Blackstone