Achim Denig and Hartmut Wittig, both project leaders in CRC 1660, are members of the Steering Committee of the international Muon g–2 Theory Initiative, which coordinates theoretical efforts and key publications such as the widely cited White Paper. Hartmut has been part of the committee for some time, and Achim has recently joined. The initiative plays a central role in interpreting the latest, most precise measurement of the anomalous magnetic moment of the muon.