Q. Is Q&A an acronym or an abbreviation? When using Q&A in, say, a training in PowerPoint, do you need to write out “Questions and Answers” the first time, like you would in an acronym, or does it stand on its own as Q&A?

A. Q&A is a pair of initialisms joined by an ampersand; as such, it’s an abbreviated form of the abbreviated expression “Q and A.” And because “Q and A” is widely known (and has its own entry in Merriam-Webster), there is no need to spell out either form the first time you use it. For a discussion of acronyms and initialisms (both of which are types of abbreviations), see CMOS 10.2; for the absence of spaces in Q&A, see CMOS 10.10.