This is the 4136th most frequent Russian word.
рсфср
The Russian word "РСФСР" stands for "Russian Soviet Federative Socialist Republic," a constituent republic of the former Soviet Union.
In this sentence, 'РСФСР' refers to the Russian Soviet Federative Socialist Republic, specifically as the largest administrative division of the former USSR.
РСФСР была частью Советского Союза.
The RSFSR was a part of the Soviet Union.
Here, 'РСФСР' is used to describe the legal and administrative framework established during the time of the Russian Soviet Federative Socialist Republic.
Многие законы РСФСР перешли в современное российское законодательство.
Many laws of the RSFSR transitioned into modern Russian legislation.
In this usage, 'РСФСР' signifies the entity responsible for significant historical developments within the territory of present-day Russia during the Soviet era.