An index is usually included at the back of manuals. However, in modular manuals, which must be issued in 3-ring binders, include the index at the front after the table of contents and list of figures. In a 3-ring binder, particularly larger ones, the back of the manual can be hard to turn to.
An index provides readers with a list of topics, keywords and synonyms used in the manual, and page references to where each topic is discussed. It helps readers find reference information quickly. Most readers use an index much more often than they use the table of contents so an index is a very important navigational aid.
An index should be more specific in the topics it lists than a table of contents. It should list topics from the point of view of the reader using keywords rather than just listing headings. If a topic could be referenced in several ways, include each variation (for example, include both "documentation standards" and "standards, documentation"). If there are alternative references, include those also (for example, "see also writing guidelines").
Index entries can be divided into main entries and one or more levels of sub-entries. For example:
standards
documentation, 3.2-4, 4.6-5
Using sub-entries lets you create topic categories that enable the reader to find information more quickly. Rather than having to scan the entire index for topics, the reader can look under one category and find all the topics that relate to that category.
You can refer readers simply to the appropriate module, or to the appropriate page of the module. Referencing page numbers makes the index more time consuming to maintain, but it’s more useful.
