1. Using Italics for Emphasis

Use italics (sparingly) to emphasize a word or phrase or bring attention to it.

Never operate this equipment when it has a yellow danger tag.

2. Using Italics for Foreign Words and Phrases

Italicize such foreign words and phrases as terra incognita, in vivo, and inter alia; however, if the word or phrase is commonly used in your field (e.g., in situ, et al., ad hoc, ab initio), you may omit the italics.

3. Using Italics for Hyphenated Prefixes

Italicize hyphenated prefixes (such as cis-, trans-, o-, m-, and p-) to chemical formulas.

trans -1, 2-dibenzoylethylene
trans -glycol

4. Using Italics To Cite Published Documents

Use italics for the names of books, journals, newspapers, magazines, and reports.

Clean Energy Innovators: NREL People Working to Change the World 
Applied Physics Letters
The Denver Post

In print, the titles of journal and magazine articles are listed in regular roman type within quotation marks. On the web, omit the quotation marks.

"Solar Chimney Theory: Basic Precepts"

5. Using Italics in Taxonomic Names

Unless you're discussing a genus in a general way, use italics to refer to specific genera, species, and varieties.

Clostridium thermocellum
C. thermocellum