In the 1970s, the non-commissioned officers serving under contract and holding Starshina (Master Sergeant) rank were reassigned to newly created Praporshchik rank (not to be confused with similarly named Russian Empire rank of commissioned officers); starshina was reserved for conscripts only.
The table of Soviet military ranks can see in Military ranks of the Soviet Union or in the section below (as they were the same as present military ranks of the Russian Federation).