I ask this question because I have problem with cross-reference.
For example, I have a heading with the text "My Test Heading", and I cross-reference it somewhere in my document. Then I change the heading to "Cowabunga". Then I update field for the cross-reference - and BAM - I got "Error! Reference source not found." for my cross-reference.
I know what happen there. It because when I cross-reference the heading, MS Word generates a hidden bookmark (ex: _Ref480371304), when I change the heading to other name - which mean I delete all the character of the old heading - the hidden bookmark is deleted also.
It is not good that I can't change my heading - like I want to translate a document and after translate, I have to insert the cross-reference all over again.