"We excommunicate and anathematise every heresy raising itself up against this holy, orthodox and catholic faith which we have expounded above. We condemn all heretics, whatever names they may go under [...] Moreover, we determine to subject to excommunication believers who receive, defend or support heretics." (Pope Innocent III, Lateran IV)
Also very good are the Bulls "In Coena Domini", in which heretics are excommunicated by the names of their sects.