That was the first thought that popped into my head upon reading the title. That's the problem with acronyms - namespace collisions occur far too frequently (and it's even worse in this case because both variants of PCB are used within the same technical domain). Fortunately, the authors at least bothered to define the term at the point when it is first used in the text (as is standard practice in science literature). There's nothing quite so annoying as encountering a blog full of alphabet soup that makes no attempt to define abbreviations properly.
