Regulatory Technical Standards on the required information for registration of third country firms and the format of information provided to clients was published in the Official Journal of the European Union. The RTS supplement the Markets in Financial Instruments Regulation on the provision of services and performance of activities by third-country firms following an equivalence decision with or without a branch. The RTS specifies the information necessary for registration with the European Securities and Markets Authority. The RTS requires firms to update ESMA, within 30 days, of any changes to the information provided in its application.  MiFIR requires third-country firms, before providing investment services for clients in the EU, to inform such clients that they are not permitted to perform services for clients other than eligible counterparties and professional clients within the definition of the revised Markets in Financial Instruments Directive and, furthermore, that they are not subject to supervision in the EU. The RTS provides that the notice must be provided in a “durable medium” (which includes electronic media); such that, amongst other things, it is in English or the in the official language, or one of the official languages, of the Member State where the services are to be provided.