I admit I am a former librarian with a Master’s in Library Science. While working on that degree, I took a course in professional indexing and have been a professional indexer ever since. I originally made this post for fellow students in my InDesign 2 class, but the class message system stripped out the indentations, so I am reposting it here for them
Here are a few tips on indexing that might help make your indexes easier to create and use.
A main entry (also called a main heading, but I don’t want to muddy the waters here) is an index topic that doesn’t come under another topic. A sub-entry is an index topic that comes under a main entry. Here’s an example:
cats <== this is a main entry about 6 <== this is a sub-entry
Levels refers to how many entries and sub-entry levels you have. I highly recommend having no more than three levels; most indexes do fine with just two.
cats <== this is level 1 about 6 <== this is level 2 food dishes 8 <== this is level 3
Page Numbers and Entries
If you have an index entry that refers to a lot of pages (my rule of thumb for “a lot” is more than three), create sub-entries for each of those pages. In other words, instead of having something like this:
cats 6, 8, 9-12, 37, 43
Create sub-entries for each of those pages, like this:
cats about 6 breeds 43 feeding 8 genetics 9-12 training 37
That way, your readers can more quickly find exactly what they are looking for, instead of having to check every page reference until they find it.
There are two most commonly used cross-references: See, and See Also. Normally just the words See or See also are place in italics.
A See reference sends people from a term they might be looking for to the equivalent term you actually used in the index. There should never be page numbers or sub-entries with a See reference. For example,
felines. See cats.
When should you use a See reference? If you are going to have a lot of entries under one main entry, you don’t want to have to duplicate it under another main entry. That’s a good case for See references. Otherwise you will get something like this (which, by the way, is prone to errors, as you will inevitably forget to index something under one or the other main entry):
cats about 6 breeds 43 feeding 8 genetics 9-12 training 37 ... etc.
felines about 6 breeds 43 feeding 8 genetics 9-12 training 37 ... etc.
If a main entry is only going to have two or three entries under it, then skip the See reference and index the same topics under both main entries.
cats 6, 9 felines 6, 9
See Also References
A See also cross-reference notifies people that there are related index entries under another entry. Generally a See also reference goes from a more specific entry to a less specific entry, as in the following example, where cats is more specific and pets is less specific.
cats See also pets. about 6 breeds 43 feeding 8 genetics 9-12 training 37
You would NOT normally have a See also reference from pets to cats, though you might well have a See reference from a sub-entry to a main entry, as in the following example. You would do this if that entry is going to have a lot of sub-entries of its own. You can even have more than one such See reference.
pets about 4 cats. See cats. choosing 5 dogs. See dogs.
See also references can either come at the end of the sub-entries, or at the start. Both ways are correct and there are reasons for either; I prefer to place them at the start so people know right away that there are related entries.
Note that you can have a See also reference to a general set of topics rather than to one specific topic; if you do this, place the entire See also reference in italics so people don’t get confused (in this example, so they don’t think “individual animal breeds” is a main entry).
pets See also individual animal breeds. about 4 cats. See cats. choosing 5 dogs. See dogs.
See Herein and See Also Herein
See herein refers people from one sub-entry to another sub-entry under the same main entry. It is mostly used in legal documents. See also herein is similar. You probably won’t need either.
An older index style is to capitalize all main entries whether they are proper nouns or not. That style is also considered to be more formal. More recent trends (especially in scientific literature) is to capitalize a word only if it would normally be capitalized (i.e., is a proper noun).
Main entries capitalized:
Burmese cats 12-14
Cats about 6 breeds 43 Burmese. See Burmese cats. feeding 8 genetics 9-12 training 37
Felines. See Cats.
Main entries follow normal capitalization of word:
Burmese cats 12-14.
cats about 6 breeds 43 Burmese. See Burmese cats. feeding 8 genetics 9-12 training 37
felines. See cats.
If you’ve gotten this far, thanks for sticking with me. Here are a few quick practices for people who just want to get it done:
- Every heading should have at least one index entry. Think about what the main topic is for the material under a heading, and index accordingly. You normally wouldn’t use the heading itself, but instead will use an informative index entry.
- Think of how someone might approach your book. What terms are they going to use? Are there other terms people use than what you used? Those are good candidates for See references.
- If your book is about tomatoes, then the assumed main entry for every entry in your index is tomatoes. This means you should NOT have tomatoes as a main entry. On rare occasions, you might have tomatoes as a main entry in such a book, but it should not have many sub-entries and it should have a really good reason for being there.
- For readability, your material should go no more than half a page without a heading level of some kind. This makes it easier to index as well.
If you are interested in the topic or in becoming an indexer (most indexers are freelancers), check out the American Society for Indexing’s Web site: