19.5 Presentation of indexes
Index matter is set in small type, one or two sizes down from text size, usually set justified left (ragged right) in two or more columns. Typically, the running heads are Index on both recto and verso, though two or more indexes can be differentiated according to their title, such as Author index, General index, Index of first lines.
Begin each entry with a lower-case letter unless it is for a word that is capitalized in the text. Carefully check hyphenation, italics, spelling, and punctuation for consistency with the text. Instructions for cross-referring (see, see also) should be italicized. However, ‘see’ and ‘see also’ commonly appear in roman when they are followed by italicized text:
Poema Morale, see Selections from Early Middle English
Poetics, see Aristotle
In Oxford style there is an en space between the entry and the first locator; interposing a comma is less usual nowadays. If a heading ends with a numeral (B-17, Channel 13, M25, uranium 235), a colon or comma can be added to separate it from the locator but a space is acceptable if that is the chosen style for other entries. Oxford style separates an entry from a following cross-reference with a comma but others omit the punctuation in accordance with other entries.
Separate multiple cross-references from each other with commas or semicolons:
There is no punctuation at the end of entries. Oxford style inserts a colon after a main heading when there are no locators but instead a list of subentries
income 12, 14–22, 45
taxation 9, 11, 44–9
wages 12–21, 48–50
but other styles only use the colon in this way in run-on entries but not in set-out style (see 15.5.2).
The first or only index in a work typically begins on a new recto, though subsequent indexes can begin on a new page.
The samples below show the two basic styles of typographic design for indexes, the subentries being either set out (or indented) or run on (or run in). The set-out style uses a new (indented) line for each sub entry; it is therefore clearer than the run-on style, though it takes up more room. In the set-out style, avoid further subdivision of subentries if possible, as this can result in complicated and space wasting structures. In the run-on style, subentries do as the name suggests: they run on and are separated from the main entry—and each other—by a semicolon. They are indented appropriately to distinguish them from the heading. Sub-subentries should be avoided entirely in run-on style. Take particular care that the arrangement is logical and consistent, since the style’s density makes it more difficult to read.
shields 4, 78, 137, 140; heraldic designs 82; kite-shaped 199; round 195; Viking 43, 44, 53
ships/shipping 22, 68, 85, 230–52; design and navigation 6; pirate 23; spending on 59; see also galleys; longships; piracy
Which style a publisher chooses depends on the length and number of subentries in the final index copy, and the conventions of related works. In any case, index copy must be submitted for setting with all entries and subentries in the set-out form for markup: it is easier for the typesetter to run these on afterwards, if necessary, than it is to set out an index from copy that was presented in the run-on format.
Turn-lines or turnovers (where text runs to more than one line of typescript) should be indented consistently throughout, and in set out style should be indented more deeply than the deepest subheading indentation. To save space, sub-subentries—where unavoidable—may be run on even in otherwise set-out indexes.
When an entry breaks across a page—most especially from the bottom of a recto to the top of a verso—the heading or subheading is repeated and a continuation note added during typesetting:
Viking 43, 44, 53