To understand outlining, you must understand three concepts: heading styles, outline levels, and body text.
Heading styles are built-in styles that Word provides for each level of heading in your document, from Heading 1 to Heading 9. These styles don't just carry formatting information; they also carry information about where the text fits in the hierarchy of your document. In other words, Word recognizes that Heading 1 is a first-level heading, Heading 2 is a second-level heading, and so forth.
Outline levels provide a way for you to give the same hierarchical information for paragraphs in your outline that are not headings. For example, you may have a quotation that you want to treat as a second-level element in your outline for the purposes of your table of contents.
Body text is text that is formatted with the Body Text outline level?in other words, text that does not have an Outline Level from 1 to 9 assigned to it. Typically, the paragraphs of text between headings in a document are body text. By default, text formatted in Word's built-in Normal or Body Text style carries the Body Text Outline Level. In an outline, if body text follows a heading, or if it follows other text formatted with an outline level from 1 to 9, Word treats the body text as subordinate.
Word's outlining feature works seamlessly with the heading styles or outline levels you may already have inserted in your documents. If you haven't applied heading styles, Word can add them for you automatically, while you work on your outline.
For more information about styles, see Chapter 10, "Streamlining Your Formatting with Styles," p. 329.
For more information about assigning outline levels to styles, see "Applying Outline Levels to Specific Text," p. 635.
You can't change the outline level associated with a built-in heading style. However, as you'll see later in this chapter, you can assign any outline level from 1 to 9 to other styles, and use those styles as the basis for your outline.
After your heading styles are in place, you can use them to automate many Word features. Later in this chapter, in the section "Using Word's Automatic Outline Numbering," you'll discover one of the most powerful of these features: Word's simple, quick Outline Numbering feature. You'll learn how Word can instantly number all your headings and subheads?and keep them numbered properly, come what may.