Emanuele Conte
Erice 2002
Gratian and the Ius commune
C.21 q.1 dictum post c.4:
Potest etiam utrique tamquam titulato presse set iure speciali non communi (A cleric can minister two churches but only with a special right not on the basis of a universal right).

A very early gloss clarified Gratian’s dictum by explaining:

I
dest specialis priuilegii datum papa, quia aliter non posset nisi papa dispensaret, quia de iure communi non posset (that is with a special privilege given by the pope, because otherwise he could not, unless the pope would have dispensed, because he could not  dispense an universal right). 
Heiligenkreuz, Siftsbibliothek 44, fol. 178rb.