There are tons of style guides* out there. Add to these style guides all the individual business and organization style guides, and you have to almost feel sorry for the writers and editors who have to deal with them all.
All that to say, sometimes you learn new things about style guides when you're in the midst of a job—and this happened to me yesterday. The revelation?
The AP Style Guide avoids italics at all costs.
Crazy, right? What do you do with book titles? Ship names? Magazine and journal titles? How can you emphasize a point?
Apparently, for all except the last, you revert to quotes—which in CMS are reserved for different items, such as article titles, TV shows, and chapter titles. I'd like to say that that's one less thing to remember—but really it means I have to remember to not use italics where I usually do!
About.com: "The Case of the Missing Italics"
AP vs. Chicago: "Titles"
Ask the Editor: AP on Italics
*Curious about which one you should be using for your current project? Take my "Which Style Guide is for You?" quiz!