I'm guessing that while still descriptive, this might be an outdated distinction... Here in the upper South where we can sail most of the year, zip out side panels are the norm and have been for some time. Cooler when removed in the hot summer months. Dryer put back on during our frequent wet and windy Summer thunderstorms and much warmer in the cool sailing days of late Fall, Winter and early Spring.
There are generally two styles of dodger build, excluding a hard top or Iverson "I" top..
Traditional or East Coast Stye:
East Coast dodgers do not have side zip off windows, have a larger sweeping radius to the frame, up to 18" or so, and often feature round side windows but can also feature triangular side windows or none at all.
This is the epitome of the Traditional or East Coast style dodger:
Some East Coast style dodgers don't even have side windows.
This was an East Coast dodger I had built with a West Coast radius and triangular window...
California or West Coast Style:
On a California dodger the radius bends are not as deep, often a 10" radius, and the side curtains are removable as seen here. Front windows can also be removable..
Our Dodger is a California style and the side curtains are removable: