Some diesel nicknames that are popular with the IRFCA gang - not mandatory and not officially sanctioned!
Jumbo = low nosed WDM-2 as seen here: /photos/Diesel/Sany0083
I am yet to see a 3100hp prime mover for this type of loco. The probable reason why the 2C or 3A version has never seen on the Jumbo frame (although there was a recent mail mentioning a sighting of a Jumbo that was a WDM-2C or WDM-3A) is that during the rebuilding process, the low nose is replaced with a standard short hood.
Again I have not sighted a loco that was a Jumbo before and is a regular short machine after rebuilding. Number crunching loco-spotters may know better.
On the other hand I have a pic of a Pune Jumbo that is already rebuilt (with an 'R' in the number) - the pic is in the Showcase archives. However this is a 2600hp rebuild - maybe the early examples of DCW's rebuilding programs. /photos/ShowcaseArchives-3/pajumbo
Baldy or Baldie = The first generation of DLW built WDG-2 and WDM-2C with a rounded profile for the short hood (reminding the rail fans of the forehead of a balding person..). The cab doors and driver's seating is reversed. The type of cabs have a wheel type throttle. /photos/Uploads/MAO27oct03
Bulgie = Rebuilt locos with a bulge in the side hiding the relocated centrifugal oil filter. These are always repowered to 3100hp and always rebuilt locos, hence they look like standard WDM-2 locos. /users/apub/ju/bgkt11.jpg /users/apub/ju/bgkt13.jpg
The WDP-4/WDG-4 has no nicknames as yet, however they have been referred to as the "Ugly Duckling" in some IRFCA mail.