Thank you, I will try that out tomorrow.

I am using TC fields because I need functionality to turn a level 1 style into a "heading". The only difference is that it becomes bold and slightly bigger, but you can't have two different styles at the same level in a multilevel list.

Headings go in the TOC, other paragraphs using the same style do not. The rest of the TOC is built using styles. It's really quite a pain for me and I did post about it previously - unfortunately none of the proposed ideas really worked.

Understood about the automatic updating of the TOC, that was something I'd considered but couldn't think of a solution. The macro I've got will also remove existing then add an updated TC field but that requires the user to interact with it. How would I add a nested ref field? That sounds ideal.