Charles, the styleref and seq fields are not ideal solutions, just workarounds needing advanced knowledge to re-create something a lot easier with heading styles.

The benefits of using the built-in heading series numbering for the Appendixes are:
- page number prefix appears as part of the TOC page numbers
- captions can be done with the GUI and not require fiddling field codes and restart switches
- cross-references can be inserted by finding with the heading and/or numbered paragraph categories

To be fair, a document that requires more than 8 heading levels (+ one for Appendix) is a rare beast and the document structure should be reconsidered but they do exist. In engineering firm documentation it is not uncommon for authors to want to add appendixes with around 5 numbered heading series which ideally would be a continuation of the heading series.

The built-in limit of 9 outline levels has been a thorn in the side ever since I started using Word in the 1980s. I've learned to live with the workarounds but do vary my approach from time to time as requirements change. My current approach is to use a template with 6 numbered heading levels + 2 numbered Annex levels + 1 numbered Appendix level to use my limit of 9. If authors require additional heading levels beyond any of these, they are instructed to use unnumbered styles and can choose to add Seq fields prefixes if they wish.

__________________
Andrew Lockton
Chrysalis Design, Melbourne Australia