Ah, ah! My fault! I consistenly used the wrong word 'Header' in stead of
'Heading'. Mistake, mistake! Maybe my question does make sense now. I'll
repost another time:
____________________

What's the best way to customize the Headings in my Word document? In my
document I have these headings:

Index

Foreword _______________________ II
Introduction ___________________ III
Chapter 1 Universality ___________ 1
Chapter 2 Uniqueness ____________ 2
Chapter 3 Iconicity ______________ 3
References ______________________ A

The Index is hidden in the TOC. The Foreword and Introduction are in a
seperate section, as well as the text chapters, as well as the references at
the end of the document.

I would like to add to the 'ordinary text' chapters the prefix 'Chapter x'
like you can see above. What's the best thing to do? To create a custom
'NumberedHeading 1' and changing it list properties? And create another
customized style 'UnnumberedHeading' for the Foreword, Intro and References
chapters? And a 'NotTOCHeading' for the Index header?

Or is it better to use Word's inbuilt styles? Making 'Heading 1' like
'NumberedHeading 1'. And e.g. 'Heading 6' equal to the style
'UnnumberedHeading' and 'Heading 7' equal to the style 'NotTOCHeading (and
adding respectively excluding these Headings when creating a TOC).

I guess it's the latter. I see already some advantage because I'm using
{IncludeText} fields and wouldn't like to update all normal 'Heading 1' in
all the included documents to something like 'NumberedHeading 1'.

I'd appreciate to hear some advantages or disadvantages of the mentioned
methods. Many thanks in advance!