There are 3 standard sizes used in US for diesel,
1.)
The really big one that my wife can't even pick up, that is the high volume nozzle for OTR rigs and the tanks that farmers have in the back of the PU trucks. This one will
NOT fit into a CRD, it would just barely fit if you took out the whole filler restricter insert.
2.) Standard diesel nozzle used for PU trucks & delivery vans and it may be the old leaded regular gas nozzle and this one just barely fits the hole and sometimes needs to be wiggled if you are not holding the nozzle just right. This nozzle may not be the exact old leaded gas nozzle but a newer and slightly bigger nozzle then the old leaded gas nozzle.
3.) Then there is a nozzle that I believe is the same nozzle as the unleaded gas nozzle, but may be a new size that's a little bigger then the unleaded nozzle, anyway it is most often used at the auto/PU truck pumps.
I would rather use the #3 nozzle as it is easiest to handle and does a better job of allowing to do slow fill for less foam then others.
The #1 nozzle will fill our 20 gal tank in about 10 seconds at full flow, which means you often got splash back when filling the '03 and earlier VW's that would take these nozzles. Been there, done that.
I have never done an actual search on the net but there may be other size nozzles made for the commercial filling station use but I doubt that is the case, probably just some of the old nozzles from the leaded gas days still around in warehouses or station parts shelves trhat end up being used on the diesel pumps for auto/PU trucks.