Definition of "subvariant"

DreamHack began in 1994, in the basement of a nearby elementary school, as a small, local subvariant of what was then called a ‘‘copyparty’’ — pre-broadband occasions to share software or demonstrate flashy off-label uses of early home computers.

2015 July 16, Gideon Lewis-Kraus, Photographs By Franck Bohbot, “Power in Numbers”, in New York Times‎