Greatest-common-divisor conjecture for zeta functions of \Upsilon-schemes

Let an $\Upsilon$-scheme be given, together with the collection of polynomials associated with its counting data. Greatest-common-divisor conjecture. The zeta function of an $\Upsilon$-scheme is the greatest common divisor of these polynomials. The source gives no further definition of the collection of polynomials or evidence that the conjecture has been resolved.