Although there are many specialized rules for capitalizing letters, the following four are the most common.
1. Capitalize the first words of sentences, including sentences cited in quotations:
2. Capitalize proper names, including any particular person, object, place, project, institution, river, vessel, genus, culture, ethnic group, or formal job title:
3. Unless you are following a documentation style that specifies otherwise, capitalize titles of books, periodicals, published and unpublished reports, articles, and document sections
Rules for Capitalizing Multiple-Word Titles and Proper Names
Unless you are following a documentation style that specifies otherwise, observe the following rules for capitalizing multiple word titles and proper nouns.
- Capitalize all nouns, pronouns, verbs, adjectives, adverbs, and subordinating conjunctions.
- Capitalize any word, regardless of the part of speech, if it is the first or last word of the title or subtitle or a proper name or if it follows a punctuation mark indicating a break in the title.
- Do not capitalize articles, coordinating conjunctions, prepositions, and the word to in infinitives unless they appear as the first or last word of a title or subtitle.
General Guidelines for Capitalizing Scientific Terms
Each discipline has its own specific conventions for determining which terms should be capitalized. In general, scientific writing tends to minimize capitalized nouns. The following list summarizes some widely observed practices.
- Capitalize and put in italics the phylum, class, order, family, and genus of plants and animals. Do not capitalize the species.
- Capitalize the names of geological eras, periods, epochs, and series but do not capitalize the word indicating the amount of time:
- Capitalize astronomical terms such as the names of galaxies, constellations, stars, planets and their satellites, and asteroids. However, the terms earth, sun, and moon are often not capitalized unless they appear in a sentence that refers to other astronomical bodies.
- Do not capitalize medical terms except for any part of a term consisting of a proper noun:
- Do not capitalize physical laws, theorems, principles, or constants except for attached proper names: