2.1 Headings
The title of this chapter, "Typography", is the first heading level. This
section, "Headings", is the second level.
2.1.1 Third-level
The third level heading. You probably shouldn't go beyond this because it just
looks ridiculous, but you can anyway.
2.1.1.1 Fourth-level
The fourth level heading.
2.1.1.1.1 Fifth-level
The fifth level heading.
Rubric Heading
A rubric heading is just a paragraph heading without document structure.