cross-references: a direction from one main heading or subheading to another.
See cross-references tell you that what you want is elsewhere (Felines. See Cats).
See also cross-references refer you to related additional information under other headings.
entry: a single record in an index, consisting of a heading followed by a locator.
double-posting: entering a topic in more than one place in the index. (Felines and also, back in the Cs, Cats)
heading: one or more terms that represent a topic or feature of the document. Indexes are largely made up of main headings and their subheadings arranged in one of two possible alphabetical orders.
inversion: the hallmark of indexes, most commonly done with names, as in Woolf, Virginia
locator: an indication (usually a page number) that refers the reader to a specific location in the manuscript. Fry, Roger, 16 sends you to page 16 where you should find something about him.
locator string: a list of locators after a heading.
locators, undifferentiated: see how I did that? I wanted to put all the locator information together. Ahem: this refers to locators after a main heading that have not been broken down into subheadings. sandwiches, 1, 16, 18, 42 is fine. sandwiches, 1, 16, 18, 42, 48-50, 62, 63, 99-104 has gotten out of control and needs to be broken down.
main heading: the first heading in a multilevel heading
multilevel heading: a main heading modified by subheadings, which may in turn be modified by sub-subheadings, which may in turn… but no more than two levels is normal, and this index will not go past the first level.
qualifier: a word or phrase added to a term to clarify its meaning or distinguish it from homographs. To use Wellisch’s examples: parties (entertainment), parties (law), parties (politics).
subheading: these modify main headings, and are used when there are too many locators for a main heading (more than six in some style guides). When there are too many undifferentiated locators, the indexer “breaks down” the main heading into subheadings to make it more user-friendly. Check out the entry for “Browne” in this index. Needs subheadings. And a first name. As do many of the others. Bad index.
term: a word, phrase, or symbol used to represent a concept.
topic: a concept, idea, or theme, explicit or implicit. The implicit ones are part of why you need a human indexer, not a keyword compiler.
undifferentiated locators: See locators, undifferentiated
Something missing here? Let me know in the comments below.