98. Among subjects that overlap choose the one that preponderates, with a reference from the other.
Ex. Any complete treatise on domestic animals will cover a large part of the ground of veterinary medicine; but it is unnecessary to enter all the works on domestic animals under Veterinary medicine; a note to this effect is sufficient. Astronomy and Geology overlap in regard to the origin of the earth, Geology and Physical geography in regard to its present condition. Any particular book must be classified with one or the other subject according as the geological or geographical treatment prevails.
(ii.) CHOICE BETWEEN DIFFERENT NAMES.
99. General rules, always applicable, for the choice of names of subjects can no more be given than rules without exception in grammar. Usage in both cases is the supreme arbiter,—the usage, in the present case, not of the cataloguer but of the public in speaking of subjects.
(f.) Language.
100. When possible let the heading be in English, but a foreign word may be used when no English word expresses the subject of a book.
Ex. Écorcheurs, Émigrés, Raskolnik. Many terms of the Roman or civil law are not exactly translatable; neither Fault nor Crime gives the idea of Culpa; the Debitor inops is not our bankrupt or insolvent; he would have been very glad to have the privileges of a bankrupt. Some other technical terms, and some names of bodies, sects, events, should be left in the original language. The use of the Latin names of Greek deities (Jupiter, Neptune, Venus, in place of Zeus, Poseidon, Aphrodite) is a manifest inaccuracy. Yet it may be defended on the plea: (1) that the Latin names are at present more familiar to the majority of readers; (2) that it would be difficult to divide the literature, or if it were done, many books must be put both under Zeus and Jupiter, Poseidon and Neptune, etc., filling considerable room with no practical advantage.
On the language of place names, see § [33], [35].
(g.) Synonyms.
101. Of two exactly synonymous names choose one and make a reference from the other.