See my answer to another question on numbering.
Those instructions are for the latest Windows versions. Here is a parallel page for the MAC versions by John Korchok. If you are using Word 97-2003 look for the link on Shauna Kelly's page for those versions.
Collapsing/Expanding paragraphs since Word 2013 has to do with the paragraph having an outline level. Paragraphs following such a paragraph with a lower level (or body text) can be collapsed.
Your following paragraph that is not collapsing must be on the same or a higher outline level.
This is related to the numbering.
Essentially, you need to link each level in such a list to an existing paragraph style. You apply the numbering in a document by applying the styles.
![define Multilevel list dialog](https://cdn.statically.io/img/i.sstatic.net/7xLfq.png)
You can do this directly by opening the normal template for editing, or using the Style Organizer to move the styles to that template. When using the Organizer, be sure to copy all of the related styles at the same time and copy them three times, overwriting existing styles. So you would want to be copying Number1, Number2, Number3, and Number4 at the same time and doing this three times.
![Organizer](https://cdn.statically.io/img/i.sstatic.net/JlCop.png)
Ouoting my page on the Organizer:
I have found it best when copying styles using the organizer to copy
them three times if any of the styles is based on other styles or is
followed by other styles. I'm not sure why this makes a difference,
but I've found that clicking on that copy button three times means
that these relationships continue in the destination template. I know
that when I copy them only once, they do not and the styles are then
followed by the Normal style.
Here is a screenshot from a new document after copying the styles using the Organizer.
![Screenshot](https://cdn.statically.io/img/i.sstatic.net/kWtin.png)
Here is a temporary link to the document in which I added the numbering. It is very important to follow the procedures in Shauna Kelly's page when creating this.
- Create unnumbered paragraph styles or use existing unnumbered paragraph styles.
- Define new Multi-Level List.
- Click on More Button
- Give list a Name
- Attach a separate paragraph style to each level
In setting up your indentation through the Define New Multi-Level List dialog you want to keep in mind how alignment of numbers work. Here is MVP Suzanne Barhill's page on Number Alignment.
Here are good YouTube videos on setting up numbering. They may help clarify the instructions. I think it may be worthwhile to first read the instructions and then watch all the videos.