26. Geographic zones or sections of the world, when used as proper nouns, take the capital, as the Tropics, the Arctics, the Levant, the Orient. When used as adjectives, use lower-case, as antarctic ice, tropical plants, oriental customs, levantine silk, morocco or russia leather, china or wedgwood pottery. Such words as india rubber, india ink, paris green, london purple, prussian blue, venetian red, roman type, gothic letter (but Gothic architecture), that describe things and are also used as nouns, do not take the capital, although they are, or are derived from, proper names.
27. Capitalize titles clearly intended as synonyms of proper names. Examples:
You will go, Major, to New York.
I am anxious about our friend, the Captain.
Mr. Speaker, I rise to a point of order.
I am, General, your obedient servant.
28. Titles not clearly used as synonyms, or when used in a general way, will not be capitalized. Examples:
He was taken before the judge.
The captain was breveted.
29. Where the word “o’clock” occurs in phrases or headlines involving the use of capitals, always set it “o’clock;” never use the form o’Clock, O’Clock, or O’clock.