The "Who is Who in Natural History Collections?" trifold leaflet is an outcome from the People Identifiers workshop/hackathon organized in Oslo in January 2023 by the COST Action MOBILISE, CA17106, supported by COST (European Cooperation in Science and Technology). The leaflet points at resources to manage biographical data in natural history collections more efficiently and contains recommendations for researchers, curators, database managers and publishers to avoid duplication of effort between collections. This publication is based upon work from COST Action MOBILISE, CA17106, supported by COST(European Cooperation in Science and Technology) and has received additional funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 101017536.