We have here the most basic of questions that must be answered before an indexer can really get to work: What is included in the index?

Sure, ok, the contents of the chapters. Obviously. But what about the introduction? And preface? What about Appendixes, or the Bibliography? Do Notes get indexed? Those poor, neglected “stepchildren” of the book… (Hans Wellisch’s words, not mine!) Generally, I do check all footnotes and endnotes for substantial content, but now I’m getting ahead of myself. Let’s answer this question properly by going through the components of a book.

The Book and Its Parts: Front to Back

*Chapter one of* The Chicago Manual of Style’s 17th edition goes into all the minute details about the different parts of books (and journals).
*Common practices of book formatting determine the layout of information, and certain sections are more likely to have pertinent information than others.* ***If there is substantive information*** *that is integral to the subject matter of the book, it may be included in the index even if the section is not typically one that is included in the index.*

One part of front matter that may sneak its way into the index, is — if present — the **list of acronyms** and abbreviations. That is, not the list itself, but the acronyms can help the indexer to know some alternate entry points or qualifiers for the index.

The Front Matter

Title pages: half title, series title (if applicable), and title page with the full book title, author name, edition number, and publisher information. Not included in the index.
Copyright page & publishing history. Also does not get indexed.
Table of Contents: until the mid-1700’s this was commonly called the Index; it listed chapter headings and summaries, subdivisions, and locators (i.e., page numbers). In some non-English speaking countries, it still is referred to as the index. TOC and lists of figures, etc., do not get indexed.
Foreword: brief remarks by someone other than the author. It does not provide substantial information about the subject of the book.
It is not indexed.
Introduction belonging to front matter: may discuss the origins of the book but generally is not integral to the text. It may be argued that the reader would be well-served to have this information findable via the index. Indexer-client communication on the topic may be appropriate.
Preface & Acknowledgments: these are the author’s own statements about the work. These are not indexed.

The Text

**Introduction belonging to text**: unlike the previously mentioned introduction, this introduction does include information pertinent to the book. *This is the first section of the book to consistently be included in the index.*

**Chapters**: multiauthored works will usually include the author’s name at the head of the chapter, and more information may be included in an (unnumbered) **footnote**. *Definitely included in the index.*

Conclusion: often does not receive a chapter number and serves to wrap up the whole discussion, and, depending on the type of text, provide implications or recommendations for the future. Just like the chapters, the conclusion is included in the index.
Epilogue or Afterword: generally, a brief commentary on the text and may serve to bring the work up to date. It is sometimes added to new editions of a book (in that case it is called an afterword). This is likely to be indexable, however, indexer-client communication may be called for on the topic.
Notes: listed in the CMOS as Endnotes under the “Back Matter” section, this one is tricky. Some books include footnotes at the bottom of each page, some include notes at the end of each chapter (especially, in my experience, in multiauthored works), and other books include all the notes or endnotes at the end of the book. Where they are located and what they are called matters less than the information they contain when it comes to their presence in the index.
Historically, the rule was to skip indexing the notes but that has changed, and they are now recognized as a potential source for valuable information for readers. The criteria for inclusion, as mentioned above, is that the notes should include substantive information, and it is now common practice to index notes as long as they provide information beyond citations.
That being said, an argument can be made (and has been, on p.55 of Mulvany’s book) for the benefits of indexing bibliographic notes if there is time and space. It usually comes down to time and price, and what the client wants.

The Back Matter

Appendixes: may include explanations or expansions of the subject matter discussed in the main part of the text but which are not essential. They may also include documents, lists, survey questionnaires, or charts and tables. Appendixes may or may not be included in the index, depending on their content, form, and the space allowed for the index. It is also possible to index their presence without going into detail about their contents.
Chronology: this may also appear in the front matter.
As with any appendixes, the chronology’s indexability will depend on its content — whether the details it provides are substantive and would be beneficial for readers to find via the index; the length of the chronology and space allotted for the index may also be determining factors. It is possible that the simple reference to a chronology of events (as with the appendixes) will be enough to balance reader needs with space restrictions.
Glossary: an alphabetical listing of special vocabulary appearing in the text. Glossary terms are typically concepts that have been deemed important by the author or editor and should be indexed — they will most likely have subheadings based on discussion in the text. Their glossary entry will likely be indexed as a subheading: “defined” or “definition.”
Bibliography or Reference List: like the “Notes” section, this may follow each chapter or be collocated at the end of the book, before the index. Unlike the notes, bibliographies usually include a complete citation of works referenced in the text. Generally, this section is not indexed.
Index: I had to include it! No, the index does not get indexed, although that would be interesting to see…

Determining What Gets Indexed

While there are some general rules for what gets included in the index and what does not, there needs to be room for improvisation based on the format and contents of the book and anticipated reader needs.

Space and time restrictions for the index will often play a role on what gets indexed, but a client can always ask the indexer to include certain features (chronology, bibliography, appendixes, etc.) that are not typically automatically included.

Similarly, if the indexer sees that inclusion of one of those extra features may seriously benefit the reader but will increase the cost or time required for indexing, the matter should be brought up with the client.

Bibliography

The Chicago Manual of Style. Chicago: University of Chicago Press, 2017.

Stauber, Do Mi, Facing the Text. Eugene, OR: Cedar Row Press, 2004.

Mulvany, Nancy C., Indexing Books. Chicago: University of Chicago Press, 2005.

Wellisch, Hans H. Indexing from A to Z. New York: H.W. Wilson, 1995.

Indexable Pages: What to Include