What does full name or name in full means

What does “full name” or “name in full” means?, because I expanded my surname when the “full name” or “name in full” is asked. All my certificates ,from KG to PG, have my name as D. Venugopal s/o D rajagopal. Because of expansion of my surname i got some additional certificates with name Dine Venugopal s/o Dine Rajagopal