Concreteness in titles makes for rapid comprehension and interest.
Clean-cut mental images are called up by specific words; vague ones
usually result from general, abstract terms. Clear mental pictures are
more interesting than vague impressions.

SUB-TITLES. Sub-titles are often used to supplement and amplify the
titles. They are the counterparts of the "decks" and "banks" in news
headlines. Their purpose is to give additional information, to arouse
greater interest, and to assist in carrying the reader over, as it were,
to the beginning of the article.

Since sub-titles follow immediately after the title, any repetition of
important words is usually avoided. It is desirable to maintain the same
tone in both title and sub-title. Occasionally the two together make a
continuous statement. The length of the sub-title is generally about
twice that of the title; that is, the average sub-title consists of from
ten to twelve words, including articles and connectives. The articles,
"a," "an," and "the," are not as consistently excluded from sub-titles
as they are from newspaper headlines.

SOME TYPES OF TITLES. Attempts to classify all kinds of headlines and
titles involve difficulties similar to those already encountered in the
effort to classify all types of beginnings. Nevertheless, a separation
of titles into fairly distinct, if not mutually exclusive, groups may
prove helpful to inexperienced writers. The following are the nine most
distinctive types of titles: (1) label; (2) "how" and "why" statement;
(3) striking statement, including figure of speech, paradox, and
expression of great magnitude; (4) quotation and paraphrase of
quotation; (5) question; (6) direct address, particularly in imperative