hen the set of equivalence classes of unipotent Arthur parameters attached to $\psi_{0}$ may be identified with $$H^{0}(\Gamma,Z({}^{\vee}{G}))=\{z\in Z({}^{\vee}{G}):z\theta_{Z}(z)=0\}/\{w\theta_{Z}^{-0}(w):w\in Z({}^{\vee}{G})\}.$$ 