The Associated Press sends out periodic updates of its oft-maligned stylebook, and one can tell what’s been happening in the news by the words and phrases that AP chooses to define, update or clarify.

It the latest update, we got definitions and clarifications on a rapidly growing category: Islamist terror groups, including al-Qaida, al-Qaida in the Arabian Peninsula, Nusra Front, al-Qaida in the Islamic Maghreb and Khorasan group. That made sense, given current events in the Middle East and the difficulty in keeping up with splinter-group proliferation.

AP also clarified “drive-by,” as in drive-by shooting; GMO, as in genetically modified organisms; IRS, which is now acceptable in all references; “ride sharing,” the best part of which was “see Uber”; and “seat belt,” which is two words, but also is “safety belt.”

A couple of years ago AP started a new section of food-related terms and definitions in light of the increasing over-coverage of food, health and recipes in many newspapers. In addition to cautioning us to spell it “blue,” not “bleu” cheese, we were told “parkerhouse roll” is not capitalized, but “Rice Krispies” is, and to avoid the use of “preheat” because we should simply “heat the oven to 350 F.”

Which brings me to my favorite part of this update:

“Icing — Use to describe sugar decorations applied to cookies; use frosting for cupcakes and cakes.”

Who knew there was that fine of a distinction? AP knew, that’s who.

Which is just the icing … er … frosting on the cake!