These rules are often modified in long bibliographical lists, tables, or other cases when following them would cause a great accumulation of italics and spoil the appearance of a page. Do not italicize the books of the Bible (canonical or apocryphal) or titles of ancient manuscripts, or symbols used to designate manuscripts.
VII. Italicize _see_ and _see also_, in indices and similar compilations when they are used for cross-reference, and when it is desirable to differentiate them from the context.
VIII. Italicize _for_ and _read_ in lists of errata to separate the incorrect from the correct.
IX. The phrases _prima facie_ and _ex officio_ are sometimes used to qualify the nouns which follow, and sometimes used as adverbs. As qualifiers they are often printed in roman with the hyphen.
Prima-facie evidence. An ex-officio member of all committees.
When used as adverbs they may be printed in italics without the hyphen.
The evidence is, _prima facie_, convincing. The speaker is, _ex officio_, the chairman.
X. Names of ships, especially when they are taken from places, as in the United States Navy, are often italicized.
XI. Names of paintings, statues, musical compositions, and characters in plays are sometimes italicized. This is not ordinarily advisable. It violates the rule of never using italics or other emphasizing devices needlessly and is liable to mar the appearance of the page. It is sometimes necessary, however, to avoid ambiguity. For example, Julius Caesar is a historical personage, "Julius Caesar" is one of Shakespeare's plays, _Julius Caesar_ is a character in the play.
XII. Italicize the symbols _a)_, _b)_, _c)_, etc., used to indicate subdivisions when beginning a paragraph and _a_, _b_, _c_, etc., affixed to the number of verse, page, etc., to denote a fractional part.
See Chap. iii, sec. 2 _a)_. Luke 4 : 31 _b_.
XIII. Italicize letters used to designate quantities, lines, etc., in algebraic, geometrical, and similar matter, and in explanation of diagrams and illustrations.
(_a_+_b_)² = _a²_+2_ab_+_b²_; the line _a c_ = the line _a b_; the _n_th power; at the point _B_.
XIV. Italicize particular letters of the alphabet when referred to as such.
We use _a_ much more frequently than _q_.