Če sta dve ali več pogodbenic že sklenili sporazum ali pogodbo v zvezi s področjem, ki ga obravnava ta konvencija, ali kako drugače uredili svoje odnose v zvezi s tem področjem, imata pravico, da namesto te konvencije uporabljata tak sporazum ali pogodbo ali da ustrezno uredita takšne odnose, če to olajšuje mednarodno sodelovanje.
3 If two or more Parties have already concluded an agreement or treaty in respect of a subject which is dealt with in this Convention or otherwise have established their relations in respect of that subject, they shall be entitled to apply that agreement or treaty or to regulate those relations accordingly, in lieu of the present Convention, if it facilitates international co-operation.