When you see someone who has the title CMO, what do those three letters mean to you? To physicians, we interpret CMO to mean Chief Medical Officer. To the rest of the world, CMO means Chief Marketing Officer.
We all know CEO, COO, and CFO. The C-suite can be an interesting place when you have a CMO as well. Hospitals may also have a CMIO or Chief Medical Information Officer.
Here's what Wikipedia has to say about the C-suite:
The highest level executives are usually called "C-level" or part of the "C-suite", referring to the 3-letter initials starting with "C" and ending with "O" (for "Chief __________ Officer"); the major traditional such offices are Chief Executive Officer (CEO), Chief Operations Officer (COO), and Chief Financial Officer (CFO). In technology companies, a Chief Technology Officer (CTO) is also central, and for companies with a strong IT capacity a Chief Information Officer (CIO) is also significant. (Most other C-level titles are not universally recognized, and tend to be specific to particular organizational cultures or preferences.)