The lexicon of the top500 ( The Encyclopedia for Classification Codes ) explains the codes and definitions in the world of economical classifications.
CPC Code 3337 Fuel oils n.e.c.
The CPC Code 3337 is described as
Fuel oils n.e.c.
It belongs to the code group
CPC Code 333 Petroleum oils and oils obtained from bituminous materials, other than crude; preparations n.e.c. containing by weight 70% or more of these oils, such oils being the basic constituents of the preparations