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The article below appeared in Key Words, the newsletter of the American Society of Indexers, Volume 9/number 3 (May/June 2001).

Cross-References: Beyond the Usual


In creating programs to convert indexes and validate cross-references in indexes, I have dealt with an unexpected variety of cross-reference forms over the years. This article will share some of the more unusual types that appear in such larger reference works as encyclopedias and legal publications. These reference sets are often updated annually or even monthly. Thus it is necessary to maintain the indexes in an on-going, and sometimes cumulative, fashion unlike back-of-the-book indexes which may be published once and never again.

Please note that all examples herein are presented in a consistent display for this article and not in the display style that may have been utilized in the original print version. The published styles, however, do vary quite a bit: cross-references are attached at the end of the entries or set on separate lines; they are punctuated with periods, commas, or in parentheses; with initial caps or not, they are typeset in bold or italics, etc. I will focus here on the textual differences. I have also simplified the examples by not showing any attached locators or extraneous subheadings.

As you'll see, it is advisable to have some user instructions accompanying these types of cross-references. Even an experienced indexer might not know how to properly use them!

The Usual

I will begin by describing the basic see cross-reference and its sibling, the see also cross-reference. A see cross-reference refers the user to the postable terminology for a concept.

see Ketchup

A see also cross-reference identifies additionalconcepts which may be of interest to the user. They may be broader or narrower terms or related subjects.

see also Chants; Dance; Instruments

As shown in the example above, the user is sometimes referred to lists of concepts. This is more common with see also cross-references. However, lists can be helpful with synonymic see cross-references especially where there is semantic ambiguity:

see Monetary demominations; News awareness

In an outline-structured index, a cross-reference may occur at a subheading level and refer to appropriate main headings:

Animal husbandry
see Horses

Generic Referrals

Sometimes a concept may not be indexed as an aggregate term because a laundry list of the individual headings would be too lengthy to display. In these situations a lead-in word can be used along with a generic phrase to indicate that the user should look for distinct headings.

see individual country names
see particular type of tax

In some situations, the indexer may decide to present some examples to guide the user to the type of headings that have been used.

Health care facilities
see specific type, e.g., Hospitals; Clinics

Other Lead-in or Trailing Words

Since these types of indexes are often used repeatedly by professional researchers who may be familiar with the heading terminology, when a previously existing heading is changed, it may be useful to redirect (i.e., retrain) the user to the new term of art. Cross-references serve this purpose and sometimes employ another lead-in word to inform the user that this is the new term.

Department of Employment Services
see now Job Services Division

Another method is used to tell the user that the topic being referred to does not include any entries relating to the current heading. In the example below, the main heading Cable television does not include any entries about Counties and that is why the "generally" has been added.

Cable television. see Cable television, generally

Editorial Notes

On occasion, to present enough useful information to the user, an editorial note is necessary which itself contains a cross-reference:

COBRA health care continuation coverage
Ed. Note: COBRA is a federal requirement. For state requirements, see specific state.

Referrals to Subheadings

So far the cross-reference examples have referred to the highest-level topics, i.e., main headings. In very large indexes, a heading may have so many subheadings that it is necessary to direct the user to a specific entry within a lengthy subheading list. By lengthy, I mean that a main heading, or even a subheading, could run over several columns or even many pages. This entry

see House pets, subheading: Cats

directs the user to the entry:

House pets

An alternate phrasing of this type of referral is

see House pets, at Cats

Yet another form of this type of referral reverses the text of the two heading levels but refers to the same destination entry:

see Cats, under House pets

Instead of subheading:, the word subhead: or subtopic: is sometimes used. A plural form is used when two or more subheadings are referred to:

see License Costs, subheadings: Charges; Fees

This eliminates the need to repeat the main heading portion of the cross-reference, which saves space, especially when headings are long as in the name of an act (e.g., Comprehensive Environmental Response, Compensation, and Liability Act or CERCLA).

Referrals within a Main Heading

Many indexers refer to the types of cross-references discussed so far as "external" cross-references. That is, they refer the user from one main heading display to another. The term "internal" is used for cross-references that refer the user within a single (lengthy) main heading. For instance, printing the main heading in this cross-reference is redundant since it is under the main heading already:

House pets
              Felines. see House pets, subheading: Cats

It is shorter and more helpful to the user to inform them that the appropriate entry is a subheading under the current main heading.

House pets
     Felines. see Cats, this heading

Instead of the phrase this heading, publishers may use one of the following variants:

under this index heading
in this index heading
this index heading
within this heading
this topic
in this topic
under this topic

Another form exists that places the informational word ahead of the term:

House pets
Felines. see subheading: Cats

Referrals within a Subheading

You might think subheading referrals within a lengthy heading display are sufficient but some indexes (containing hundreds of thousands of entries) use another trailing phrase that lets the user know the cross-reference is to another entry within the current subheading.

Domesticated Animals
House pets
Felines. see Cats, this subheading

Again this informs the user that they are near the proper subheading term.

Positional Phrases

There are some alternate forms of the last two situations. A positional word or phrase is used to indicate to the user the proper direction, either up or down, to browse from the point of the cross-reference. For instance, the example used in the section Referral within a Heading would appear with a positional phrase thus:

House pets
Felines. see Cats, ante

If the subheading being referred to is "down the page" from the cross-reference entry, then the word used is post. I've also encountered a phrase combining the two forms so the trailing phrase would "see Cats, ante, this heading."

Similarly, the example used for the section Referral within a Subheading would appear with a positional phrase thus:

Domesticated Animals
House pets
Felines. see Cats, ante this group

Here are the positional indicators that I have encountered:

   ante     above     supra 
   below     infra 

Generally though, usage is moving away from the positional indicators in favor of the generic this heading and this subheading since these require less re-validation as the index is edited. (Perhaps users do not find the Latin terms very friendly.) If you have to move a cross-reference to a different heading, due to a change in terminology, what was an ante may now become a post reference. This is one more thing for the indexer to remember to do (or fix after running software validation).

Not a see to be Seen

There are even indexes with cross-references that don't use the word see to begin them. You have to recognize a cross-reference by a trailing phrase. An example would be

             Gambling and gaming, this index

You might think this refers the user simply to the main heading "Gambling and gaming" but in fact it does more. The user needs to find the subheading "Bingo" under this main heading. That is, the entry referred to is:

Gambling and gaming

This "transpositional" thinking takes getting used to and definitely requires head notes to educate new users of the index. Indexes using this referral form often utilize the positional indicators discussed earlier but still without any see lead-in. For example,

License and license taxes, below


As one might suspect, all of these types of cross-references were developed over many years by different companies. As publishers have moved their index data, from paper or mainframe systems, to dedicated indexing software, some have chosen to forsake the less common forms and change their style. However, some publishers think that long-time users are wedded to the cross-reference wordings, or that it is too costly to alter and re-check all the thousands of existing cross-references, so the various forms persist.

Software Issues

The cross-references presented in this article can be entered and formatted for publication with the available dedicated indexing software packages, but none of these packages handle all of the types shown here when running a verification process.

If you have a project that uses any of these cross-references, expect to spend extra time dealing with the verification of these less common common cross-references. Except for locator errors (bad page numbers, for instance), nothing confuses or frustrates researchers more than following cross-references that are circular or point to a non-existent heading.

Some publishers have created their own special software for performing verification but it is often usable only on their mainframe system for their specific wordings. If you have a large project or consistent work from a client, you may find it cost effective to commission customized software or find an off-the-shelf utility, such as LevTech's SumDex program, that may work for the project.

In Closing

I hope that you've seen some cross-references here which you've not encountered before. Maybe some might be helpful to you on a future project! Just remember to provide an explanation in the head notes for any unusual references.

Many times I thought that I've seen all the possible cross-reference wordings out there, but I've always been wrong; so now I just wait to come across the next one. Send me any examples that I may not have covered so I can add them to my growing library.