Using previously un-used heading levels would be more suitable for situations where you want to maintain two separate numbered lists that both make use of the "magic" properties of the built-in headings; for example, this would be the case when you set up appendix numbering as discussed in the article at https://shaunakelly.com/word/numbering/numberingappendixes.html.
Word's Numbering Explained by John McGhie, MVP - comprehensive and not pretty (Downloadable pdf file in letter size) - Reading this is vital to anyone attempting to use automatic numbering or bullets in a law office setting or other places where the documents are likely to be reused or heavily edited. See also How to Create a Template with a downloadable template with style-based numbering. I strongly recommend that you read both of these before doing anything with the contents of this chapter.
The values for Number position (here called Aligned at), Text indent and Follow number with are in the Position section at the bottom. With multi-level numbering, you also have easy access to settings that control the type of numbering at each level, the characters before and after each level’s numbers (period versus parenthesis), and the list number style (1, a, I, etc.).
The heading here could be anything: affirmative defenses in an answer, articles in a contract, etc. It doesn’t matter; the technique is the same with only slight variations. The result is that you’ll have a heading saved in your Quick Parts that will be numbered correctly, no matter how many items you add or delete. This makes this technique particularly useful in building templates for common documents; because it’s always easier to delete than add, they’ll re-number themselves after editing.
Running captions number figures, tables, and other items consecutively in a document. For example, the first figure caption starts with the words “Figure 1,” the second with “Figure 2,” and so on. To make sure that figures, tables, or similar items are numbered consecutively, define a list for the item, and then create a paragraph style that includes the list definition. You can also add descriptive words such as “Figure” or “Table” to the numbering scheme of the paragraph style. numbering using publisher