24. States use nationality recognition procedures based on witness testimony (possession d’état), or other flexible means of nationality acquisition, in order to facilitate access to nationality for all persons with a strong link to the State but who do not have, and cannot obtain, proof of their identity or of their nationality. Abidjan, 30th September 2015, the participants 16 In the context of the fight against transnational crime, we undertake to manage civil registration data taking into account both the need to combat identity crimes and to prevent and reduce statelessness, and urge ECOWAS and UNHCR to promote collaboration among Member States for this purpose 17 We urge relevant ECOWAS institutions to study how migration within West Africa and migration originating from West Africa can lead to situations of statelessness and to propose practical measures , premised upon collaboration with Member States, to facilitate confirmation of nationality of nationals abroad and to promote issuance of identity documentation to nationals abroad 7