3   Structure and Organization

Numbering Systems

Several different numbering systems are sometimes used in manuals, each with a different purpose:

• module numbering
• heading numbering
• paragraph numbering
• page numbering
• figure numbering

Numbering systems are used to help readers find information in print publications. Numbering provides a method of locating elements of the manual without having to scan every page and heading.

Avoid Roman numerals, particularly higher than 15 (xv). Many people have long forgotten how to read them, and those who do remember are usually slower at it.

Module Numbering

In revisable manuals, since the pages aren’t numbered sequentially from the beginning to the end of the manual, page numbers are not the primary means of locating information. Instead, we number the modules, then number the pages sequentially within each module. In a sectional manual, the module number and the page number are usually combined (for example, 3-14). In 2-level modules, the module number is usually a compound number consisting of the chapter number and the section number (for example, 5.2). In 3-level modules, the module number is a compound number consisting of the chapter number, the section number, and the sub-section number (for example, 5.2.3). See Figure 3-9.

Figure 3-9: Sample module numbering

Some people prefer an expanded numbering system that leaves gaps in the number series for future additions to the manual. Instead of numbering modules 2.1, 2.2, and 2.3, they number them 2.10, 2.20, and 2.30. Later, new modules, such as 2.25, can be inserted between 2.20 and 2.30. If needed, the chapter numbers can also be expanded. While this strategy provides more flexibility for inserting new modules, it complicates the numbering system, often unnecessarily.

In online manuals, where the user locates the module (topic) by clicking on its title, not by thumbing through the pages, module numbering is unnecessary. Where you need both print and online versions of the same manual, you may want to continue to use the module numbers in the online manual for consistency.

Heading Numbering

When typewriters were used to create manuals, authors often used heading numbering to reinforce the hierarchy—each heading in the manual had a number beside it. This was necessary because authors couldn’t use other typefaces or type sizes to show each heading’s place in the hierarchy. Now that other typefaces and type sizes are readily available, it’s no longer necessary to use heading numbering in either print or online manuals, and this practice is fading. See Figure 3-10.

Figure 3-10: Sample heading numbering

Paragraph Numbering

Some types of documents use a numbering system to number every paragraph and list item. This is common in legal acts and regulations, as well as in technical specifications. Numbering each paragraph and list makes it easy to cross-reference or cite specific parts of the document. For example, in a manual of electrical standards for buildings, you could cite the standard for breaker switches by simply referring to the paragraph number. Normally an alphanumeric numbering system is used, which mixes numbers, letters, and sometimes Roman numerals. Paragraph numbering is seldom used or necessary in other kinds of manuals. See Figure 3-11.

Figure 3-11: Sample paragraph numbering

Because of its usefulness in cross-referencing, paragraph numbering is appropriate in both print and online manuals of this type.

Page Numbering

Pages in a modular print manual are numbered sequentially only within a module. When a new module begins, the page numbering starts at page one again. The page numbering is usually separate from the module numbering so they are not confused.

In an online manual, page numbering is meaningless and should be dropped since pages no longer exist.

Figure Numbering

Figure numbering is often used in manuals that have a lot of illustrations, tables, or diagrams. All numbered figures should have captions (see Figure 3-12). Only number the figures where you intend to refer the reader to the figure. Do not number graphics that are used for visual appeal only. Figure numbering is usually sequential within each module. For example, in module 5.2, the figures would be numbered 5.2-1, 5.2-2, and so forth.

If you are planning to include a list of figures at the front, give each figure a title as well, so you have something to refer to.

Figure 3-12: Use a caption to explain the significance of the figure

Figure numbering is unnecessary in online manuals since figures are usually accessed with a link and not by reference.