Linnik–Ibragimov universality conjecture for meromorphic Dirichlet series

Let $f(s)=\sum_{n=1}^{\infty}a_n e^{-\lambda_n s}$ be a Dirichlet series that is meromorphically continuable to the left of its half-plane of absolute convergence. Linnik–Ibragimov universality conjecture. All such functions are universal in some suitable region.

This conjecture asks how broadly universality extends beyond the established examples of zeta-functions and $L$-functions. The source gives no further hypotheses or resolution status.