MLA does not have a prescribed system of headings for books (for more information on
headings, please see page 146 in the MLA Style Manual and Guide to Scholarly Publishing,
3rd edition). If you are only using one level of headings, meaning that all of the
sections are distinct and parallel and have no additional sections that fit within them,
MLA recommends that these sections resemble one another grammatically. For instance, if
your headings are typically short phrases, make all of the headings short phrases (and
not, for example, full sentences). Otherwise, the formatting is up to you. It should,
however, be consistent throughout the document.
If you employ multiple levels of headings (some of your sections have sections within
sections), you may want to provide a key of your chosen level headings and their
formatting to your instructor or editor.
Sample Section Headings
The following sample headings are meant to be used only as a reference. You may employ
whatever system of formatting that works best for you so long as it remains consistent
throughout the document.
1. Soil Conservation
2. Water Conservation
3. Energy Conservation
Level 1 Heading: bold, flush left
Level 2 Heading: italics, flush left
Level 3 Heading: centered, bold
Level 4 Heading: centered, italics