Canon 146

1. The territory of the Church over which the patriarch presides is extended to those regions in which the rite proper to

the same Church is observed and the patriarch has the legitimately acquired right of erecting provinces, eparchies as well as

exarchies. 2. If a doubt concerning the territorial boundaries

of the patriarchal Church arises or if it is a case of the modification of boundaries, the synod of bishops of the patriarchal

Church is to investigate the matter, having heard from the superior administrative authority of each Church sui iuris concerned,

and, having discussed the matter in the same synod, to direct an

appropriately prepared petition proposing the resolution of the

doubt or the modification of the boundaries to the Roman Pontiff,

who solely can authentically resolve the doubt or issue a decree

modifying the boundaries.