The Young Communist League (YCL) is the name used by the youth wing of various Communist parties around the world. The name YCL of XXX (name of country) originates from the precedent established by the Communist Youth International.
Examples of YCLs:
In the Soviet Union the YCL was known as the Komsomol.
The corresponding youth organization in China is usually translated as Communist Youth League.
References
Young Communist League Wikipedia(Text) CC BY-SA