Allowing 3rd parties to interoperate with the gatekeepers own services is one of the core obligations... > Gatekeepers should ensure interoperability for third

Allowing 3rd parties to interoperate with the gatekeepers own services is one of the core obligations... > Gatekeepers should ensure interoperability for third-party providers of number-independent interpersonal communications services that offer or intend to offer their number-independent interpersonal communications services to end users and business users in the Union. To facilitate the practical implementation of such interoperability, the gatekeeper concerned should be required to publish a reference offer laying down the technical details and general terms and conditions of interoperability with its number-independent interpersonal communications services. > ‘interoperability’ means the ability to exchange information and mutually use the information which has been exchanged through interfaces or other solutions, so that all elements of hardware or software work with other hardware and software and with users in all the ways in which they are intended to function; Maybe you are thinking of something other than the DMA?