Volumes, books, titles, acts of plays, the years of the Republican Calendar, are put in large capitals: An IV, acte V, tome VI; also numerals belonging to proper names: Louis XII; and the numbers of the arrondissements of Paris: le XVe arrondissement.
Scenes of plays, if there are no acts, are also put in large caps.: Les Précieuses ridicules, sc. V; also chapters, if they form the principal division: Joseph, ch. VI. If, however, scenes of plays and chapters are secondary divisions, they are put in small capitals: Le Cid, a. I, sc. II; Histoire de France, liv. VI, ch. VII. The numbers of centuries are generally put in small capitals: au XIXe (or XIXème) siècle.
The first word of a title always takes a capital letter: J’ai vu jouer Les Femmes savantes; on lit dans Le Radical. If a substantive in a title immediately follows Le, La, Les, Un, Une, it is also given a capital letter, thus: Les Précieuses ridicules. If the substantive is preceded by an adjective, this also receives a capital letter: La Folle Journée; if, however, the adjective follows, it is in lower-case: L’Âge ingrat. If the title commences with any other word than le, la, les, un, une, or an adjective, the words following are all in lower-case: De la terre à la lune; Sur la piste.
In titles of fables or of dramatic works the names of the characters are put with capital initials: Le Renard et les Raisins; Le Lion et le Rat; Marceau, ou les Enfants de la République.
In catalogues or indexes having the first word or words in parentheses after the substantive commencing the line, the first word thus transposed has a capital letter: Homme (Faiblesse de l’); Honneur (L’); Niagara (Les Chutes du).
If the words in parentheses are part of the title of a work, the same rule is followed as to capitals as above given: Héloïse (La Nouvelle); Mort (La Vie ou la).
The words saint, sainte, when referring to the saints themselves, have, except when commencing a sentence, always lower-case initials: saint Louis, saint Paul, sainte Cécile. But when referring to names of places, feast-days, &c., capital letters and hyphens are used: Saint-Domingue, la Saint-Jean. (See also, as to abbreviations of Saint, Sainte, [p. 82].)
I. Use capital letters as directed below:
(1) Words relating to God: le Seigneur, l’Être suprême, le Très-Haut, le Saint-Esprit.