NMG:
The coaches with age group of 20 – 21 years or later being converted to air brake coaches during POH for the purpose to carry Automobile (Express) Auto Carrier are known as NMG coaches and the rakes formed with these coaches are called NMG rakes.
HCPV:
Mainly...
more... its consider for more quantity luggage in a particular train. It carries any luggage( not 3 or more wheeler vehicles).