What do you call / how do you name your projects ?

I recently moved over from Primavera where projects are controlled from within the planning software using unique 4 character references. Now I’m managing PowerProject files from within Explorer like any other document file, I cant decide on a suitable system for naming the projects... how do you organise your projects within folders ie using a full project name, eg Bullworth High School Extension rev1, or by project ref eg C1099 rev1, or by revision and date eg Rev01 13.07.07 etc etc...

just would appreciate some different takes on your file management ....