Subentries are used to augment and define information related to the main heading. The combination of the main heading and its subentries is an entry array. In this blog post, I address subentries, which are sometimes referred to as “subheadings.” There are two types of subentries: specific and generic. See also Main Headings 101.
A specific subentry connects additional information to the main heading, and can often be flipped to create a second main heading pointing to the same information.
horses, Arabian, 6
Arabian horses, 6
courts, restorative justice and, 10
restorative justice, courts and, 10
A generic subentry does not add new information to the main heading. Instead, it breaks it down into more basic components.
table saws, types of
calculators, features of
The subentries “types of” and “features of” are not specific to their main headings, and are therefore generic.
Using the same generic subentries consistently throughout an index provides the reader with a familiar framework with which to find information. This is especially useful in indexes for textbooks and other highly formatted texts.
Subentries, best practices for
Subentries that begin with a keyword are followed by an introductory word (and, of, for, etc.). Gerunds can also be used as subentries.
Students of library and information science may recall S.R. Ranganathan’s Colon Classification, in which he divides all things into five fundamental categories: Personality, Matter, Energy, Space and Time (PMEST).
As I acquired experience as an indexer, I began noticing a pattern to subentries.
Building on Ranganathan’s five facets, I then developed a list of main heading types (people, places, things, abstract ideas, and organizations), which I mapped to my collection of generic subentries to keep as a general indexing reference. This document is available by request.