“The mandatum is fundamentally an acknowledgment by Church authority that a Catholic professor of a theological discipline is a teacher within the full communion of the Catholic Church” (http://www.usccb.org/bishops/guidelines.shtml ). The mandatum is a relational reality between a Bishop and a Catholic person teaching Catholic theology within the diocese. A Catholic teaching Buddhism, or a non-Catholic teaching church history are not given mandatums. The Bishop is expected to give the mandatum to the theologian (“If all the conditions for granting the mandatum are fulfilled, the teacher has a right to receive it and ecclesiastical authority has an obligation in justice to grant it. (Cf. http://www.usccb.org/bishops/guidelines.shtml ). The hope is that Catholic theologians will see this as a way to fulfill their calling as teachers of the faith.
In the USA, too many theologians have seen the mandatum as overbearing oversight by Bishops without the academic qualifications to judge their work. This has resulted in the unhappy situation where many theologians are much more servants of academe alone with little real or desired connection to the work of the church. Much work needs to be done on both sides of this divide to ameliorate the present state of affairs.