Martin Tulic, Book indexing - About indexing

Function words

Definite and indefinite articles, conjunctions, particles, prepositions and pronouns are function words - i.e., words that signify a syntactic relationship between nouns, verbs and adjectives.

And, as, at, for, of and other function words are sometimes considered to be unimportant because they are often ignored in normal reading. Similarly, because they are generally meaningless by themselves, they are inevitably included in the stop lists that automatic indexing programs use to exclude words from their output. Indexers, too, often eliminate them from headings because doing so saves space without sacrificing clarity, as the following example indicates:

Subheadings with function words	Subheadings without function words
New York City crime in, ... history of, ... ethnic diversity in, ... population growth of, ...	New York City crime, ... history, ... ethnic diversity, ... population growth, ...
bottom row

If the subheadings without function words in the example above are as clear as those with them, it is because users generally assume that subheadings follow their heading in order but often precede it syntactically to form a grammatical unit. Hence, they are likely to assume that New York City: crime means crime in New York City, and not crime before New York City or crime after New York City. Because of this assumption, function words may be superfluous in cases where the subheadings precede their heading to form a grammatical unit. However, the same is not true when they follow their heading to form a grammatical unit. In these cases, function words may be needed to prevent a misunderstanding, especially when more than one relationship exists between the heading and subheadings, as in this example:

design
for reuse, ...
with reuse, ...

Of course, headings and their subheadings do not have to be grammatically related. The only requirement for a subheading is that it be logically related to its heading. Aspect-of, class-subclass and whole-part relationships are examples of logical relationships that can be expressed without also establishing a grammatical relationship. Hence, concern about function words is not limited to cases where there is a grammatical relationship. It is a general concern because function words may be the best way to to avoid ambiguities and to clarify relations between a heading and its subheadings. They always deserve careful consideration by indexers and should never be overlooked by users.

Guidelines for using function words:

Include as few function words as possible, especially at the beginning or end of subheadings. Excessive use of function words is often the result of attempting to establish an unnecessary grammatical relationship between a subheading and its heading. For example: instead of this,

drug use
adverse effects of, ...

use this:

drug use
adverse effects, ...

Using and as the first or last word of a subheading is perhaps the most frequent violation of this guideline. And is noise because it establishes a relationship, but not a specific one. It may as well not be there.

Use function words when they are necessary to clarify a relationship between a subheading and its heading. Cases where they may be necessary include cases where there is more than one relationship between the heading and another term and cases where the subheading follows the heading to form a grammatical unit. For example:

crime
against immigrants, ...
by immigrants, ...

Note that, because a relationship is always presumed to exist between a heading and its subheading, and is always redundant because it re-states the existence of the relationship without clarifying its nature.

When all subheadings begin with the same preposition, shorten them by moving the preposition to the main heading. For example: this

testing
   by designers, ...
   by programmers, ...
   by users, ...

should become

testing by
   designers, ...
   programmers, ...
   users, ...

Don't be worried by the fact that the main heading now ends with a preposition.

Do not use a function word as the first word in a main heading. The only exception to this rule is in cases where the main heading is a formal name having a function word as its leading term, as in these examples of book titles and locations:

As I Lay Dying, ...
El Alamein, ...
For Whom the Bell Tolls, ...
My Antonia, ...
Of Mice and Men, ...
The Alamo, ...
The Hague, ...
Within a Budding Grove, ...

If necessary, provide a cross-reference to assist users who may ignore leading function words. For example:

Alamein. See El Alamein
Alamo. See The Alamo
Hague. See The Hague

Ask your editor about how to alphabetize subheadings beginning with function words. The Chicago Manual of Style, an indexing holy writ to some editors, says that leading function words should be ignored when alphabetizing because they are not important. According to it, against immigrants and by immigrants in the example above should both be alphabetized as if they began with the word immigrants. In all other standards, alphabetization is based solely on the sequence of letters, numerals and other symbols in headings. According to them, against immigrants should be placed with entries beginning with the letter a and by immigrants with entries beginning with the letter b.

Be consistent, especially when function words at the beginning of headings count during alphabetization. Most function words are not interchangeable because they establish a unique relationship between terms. For example: at signifies place and by signifies agency. You cannot use one in place of the other. However, a possessive relationship may be signified using either in or of. In the following example, in is used:

reaction time
   in adults, ...
   in children, ...
   in elderly people, ...

Alternatively, of could have been used:

reaction time
   of adults, ...
   of children, ...
   of elderly people, ...

Inconsistency occurs when different function words are used to signify the same relationship. For example:

reaction time
   during childhood, ...
   in elderly people, ...
   of adults, ...

Consistency applies to the subheadings of a given main heading and across different main headings.