Abstract The notion of weak Doi-Hopf π-datum and weak Doi-Hopf π-module are given as generalizations of an ordinary weak Doi-Hopf datum and weak Doi-Hopf module introduced in (Böhm, 2000), also as a generalization of a Doi-Hopf π-module introduced in (Wang, 2004). Then we also show that the functor forgetting action or coaction has an adjoint. Furthermore we explain how the notion of weak Doi-Hopf π-datum is related to weak smash product. This paper presents our preliminary results on weak Doi-Hopf group modules.
