Q. Based on CMOS 10.4 (“Use no periods with abbreviations that appear in full capitals, whether two letters or more and even if lowercase letters appear within the abbreviation: VP, CEO, MA, MD, PhD, UK, US, NY, IL”), Los Angeles should appear as LA, but this can create confusion between the city and the state of Louisiana. How then do you treat Los Angeles when you need to abbreviate it?

A. Los Angeles is also abbreviated LA. If you spell out Los Angeles at first mention, it’s not likely that readers will suddenly think you are talking about Louisiana when they encounter “LA,” but in any context where the abbreviation is potentially confusing, avoid using it.