indexes: syntax of heading

Definite and indefinite articles, adverbs, and finite and infinitive verbs should not be included in headings or subheadings except in the case of headings comprising titles of publications and works of art. The only verb form permitted is the gerund. Retain conjunctions and prepositions essential to establishing a semantic link within the headings. Some latitude is possible here, however. Note that there is no prepositional link between the heading “Muscles, skeletal” (see indexes: complex entry) and the subheading “hypertrophy, inherited”; the reader will understand the semantic relationship between the two items, and the columnar presentation shows that one is an aspect of the other.

In determining the word order of a heading, the first step is to select a keyword or phrase under which to list the entry. For example, an indexable subject in a social science manual might be the sources and collection of statistical data. Statistical data would be the key term and the entry would appear thus:

• Statistical data, sources and collection of, 57

Sources and collection cannot be used as a key phrase because it is not specific enough. Accordingly, the normal word order has to be inverted and a comma is required after the key phrase. Inversion serves to reduce scattering of related headings and page numbers throughout an index because headings with the same key word will be located close together, e.g. Heating, electric and Heating, oil-fired.

An action word (gerund) in a heading is normally brought to the fore if the entry is listed under a noun:

• Mean, determining standard error of, 35

In the interest of brevity, however, the gerund in the above example could be dropped, since the reader will realize what is entailed in the reference.

Another way of achieving conciseness is to drop prepositions. In the following example, the key phrase is followed by a logical sequence of modifiers:

• Copper ores, mining, grinding, screening, pulverizing and floating

With the key phrase in boldface type, the preposition of can be dropped without causing the reader any problems of comprehension.

An adjective is inverted unless it is part of a name and the noun itself is non‑specific:

• Oral cavity
• Pulmonary disease