Confusion is arising because "pentatonic" has more than one meaning, and they are not unterchangable (much like "folk"). It can mean a scale with five notes in it(any five notes). But it also has the specific meaning(more commonly used) of a five note scale using five notes with a specific relation to each other (eg CDEGA, and the scale can start on any one of those). If two people are talking about this, you have to decide which meaning you are using if you want to avoid confusion.