What an appendix is in a book, what belongs in one, and how to set it up

What an appendix is

Scribe's guide to the parts of a book defines an appendix as additional content that is useful to the reader but would have disrupted the flow of the chapter where it was referenced. Its purpose is to supplement what the reader learned in the main text. The same guide notes that you can have different appendices for different types of information, and that most books do not need one.

The test is simple: if a reader can follow the chapter without it, but would be glad to have it, it may belong in an appendix.

What nonfiction authors put in one

• Templates and worksheets the chapters refer to, in full, so readers can copy or photocopy them.
• Checklists and scripts readers will come back to after finishing the book.
• Data and research: full survey results, detailed tables or methodology that would bog down a chapter.
• Timelines and reference lists, such as key dates or a list of the people in the story.
• Longer case studies that support a chapter's point but run too long to include in it.
• Original materials: Scribe's guide notes that in biographies or memoirs, an appendix can include original materials like photos and letters.

Scribe's guide to prefaces, forewords and introductions makes the same point from the other direction: if your book requires extra material, put it at the back, for example your data in an appendix, rather than loading up the front.

Appendix, notes, glossary or resources?

Does your book need one?

Probably not. Add an appendix only if at least one of these is true:

• A chapter refers to a tool, template or worksheet the reader is meant to use, and it is too long to print in the chapter.
• You have data or documents that support your argument and that some readers will want to check.
• Readers will come back to the material after they finish the book.

If what you want to add is really a summary, it belongs in the conclusion. If it is a single citation or aside, it belongs in the notes. If it is a list of terms, make it a glossary.

How to set one up

1. One kind of material per appendix. Templates in one, data in another. It makes each one easier to find.
2. Label and title each one. "Appendix A: The Weekly Planning Template," "Appendix B: Survey Results." Use letters or numbers consistently.
3. Refer to it from the text. At the point in the chapter where it matters, tell the reader it exists: "The full template is in Appendix A."
4. Make it usable on its own. A reader may open the appendix months later. Add a line of context at the top so it makes sense without rereading the chapter.
5. List it in the table of contents. Each appendix gets its own line, with its letter and title. See how to write a table of contents.
6. Check permissions. If an appendix reproduces someone else's material, such as a published chart or another author's worksheet, you may need permission. Stage 4 covers quoting and permissions.

Where it goes

An appendix goes in the back matter, after the main text and its conclusion. The Chicago Manual of Style covers appendixes in section 1.66 of its chapter on the parts of a book, among the back matter. Scribe's parts-of-a-book guide lists the back matter in this order: acknowledgments, appendix, postface, notes, footnotes, bibliography or references, copyright permissions, glossary, index, list of contributors, resources, coming soon and about the author. Your publisher or designer may use a slightly different order.

For the sections that come just before it, see afterword vs epilogue and how to write acknowledgments.