It has been some years that OSM and OMSF members have been discussing the topic of OSMF local chapters over emails, wiki, physically through BoF sessions at SotM events. In 2019 the Ugandan NGO MapUganda applied to be the OSMF local chapter in this country. This talk will share lessons that OSM and OSMF members can learn about the multi-years collective dynamics around OpenStreetMap which unfold in French-speaking southern countries of Africa and the Caribbean. In these countries, since the start local OSM actions (outreach, communication, mapping and training) have been organized collectively. These actions lead to the de facto building of first informal collective of mappers which organized internally over the years and for some incorporated as local associations mandated to the promotion and support of the OSM project playing the role of a de facto OSM Chapter. The talk will look at the collective practices of these de facto OSMF local chapters in the light of the OSMF requirements but also look at the OSMF local chapters requirements in the light of this multi-years OSM associative experience with the view to identify itineraries to the building of OSMF local chapters. Like in Milano's BoF sessions, this talk will be collectively built with African mappers involved for many years in these activities and ideally co-facilitated by those from Western Africa successful in getting visas and traveling to Heidelberg. This talk is meant to introduce a BoF session opened to anyone active or interested in supporting the growth of OSMF local chapters connected to the pioneering grassroot collective in the hard environment of the countries of the Global South and especially southern countries of Africa.