It is essential to use a logical and consistent hierarchy of headings. You have to attend not only to the numbering but also to other elements of format such as style and location on the page. Do not introduce too much elaboration. Thus, under the number and title of the chapter, you should use the following six levels. You will not often need more than four.
Every heading is separated from the text by a double gap, before and after.
A quotation which exceeds five lines in length is separated from the other text and double-indented. It is not then enclosed within quotation marks. Quotations within such separated and indented material are given single quotation marks. Quoted material must exactly follow the source being quoted. It must not be put into house style.