As I look at different participants' categorization of flights, it is clear that this exercise runs the gamut from those who are very thorough (737-200, 737-300, etc.) to those who are less so.

My goal is just to be consistent, but I don't have a good enough grasp of airplanes to know whether I am accomplishing this as I move from one airline manufacturer to another. I'm looking for opinions from those who can shed some light on the subject.

For instance, if I choose just to list a 737 as one type of aircraft, should I list an MD-81, MD-82, MD-83, MD-88, and an MD-90 as 5 additional aircraft OR rather lump all of these or most of them (MD-90 possibly unique?) into a general category of MD-80's? Should 717's get their own unique category or be grouped with one of the MD-XX categories? What about Embraer 135's and Embraer 145's? CRJ100's and CRJ200's?

I understand that this probably boils down to a matter of personal preference, but I would like to make an informed decision. To put it into automobile terms, I want to avoid a situation where I have mindless classifications such as Ford, General Motors, Honda Accord LX Coupe, Honda Accord EX Sedan, Toyota Camry, Toyota Corolla, etc. Any insight on the matter would be greatly appreciated!