Hot Rods nostalgic numbers history lesson

Can you guys tell me the significance and meaning of the letters behind a number on a race car lettering. For example the C on these cars. Thanks

 

here you go.

http://www.hotrod.com/articles/hrdp-1301-salt-101-bonneville-racing-guide/

 

THANKS

 

Of course, these cars not being entered in compe***ion, the numbers are to look cool.

 

Informative read,thanks.

 

You can see on Greg Temple's roadster A/BFR. These are the more recent letters. With A being 440 to 500 inches. B being Blown. F being Fuel. Nitro, alcohol, Nos or some exotic race ga not from the ERC truck. And R for roadster. And 208 just being the Temple family number,

 

Here at World of Speed.
B=engine size up to 440 cubic inches, g= gas only fuel, r=roadster and 384 is my number ***igned by the BNI .