The European Strategy for Particle Physics will be updated by May 2020. For this purpose the CERN Council has established a strategy secretariat chaired by Halina Abramowicz. The particle physics community is invited to provide written input by 18 December 2018. The document presented below shall provide such input.
Following a discussion at the "Patras 2018" workshop at DESY in June 2018, an editorial team has writtten a document on the physics case of axions and other WISPs, the status of experimental searches and the prospects for the coming decade.