Capitalize the first word in the salutation and in the complimentary close of a letter. (See also letters.)
Dear Dr. Cervetti: Sincerely yours, Yours truly,
When specifically identified by number, certain units, such as chapters of books and rooms in buildings, are normally capitalized.
Chapter 10, Ch. 10; Room 434, Rm. 434
Minor divisions within books are not capitalized unless they begin a sentence.
page 54, section 3, line 2