V68 is the name of a mutation on the Y chromosome.
It is used as a UEP to identify the Y chromosomal clade named "E-V68", or, in phylogenetic terms "E1b1b1a".
There will probably be significantly more information posted at the article named "E-V68". This article is only about the mutation.
This mutation was announced in Trombetta et al. (2011).