Rule XV. I and O.—The pronoun I and the interjection O should always be written with capitals.
EXAMPLES.
“True faith, I tell thee,
Must ever be the dearest friend to man:
His nature prompts him to assert its rights.”—Schiller.
“As wise as when I went to school.”—Goethe.
“O day! O day! O day! O hateful day!
Never was seen so black a day as this.”—Shakespeare.
Rule XVI. References.—In referring to passages in books, numbers are sometimes represented by capital letters.
EXAMPLES.