Congress participants are welcomed to submit their oral or poster contribution to the Congress Proceedings. These will be published as an issue or a section of an issue of Arachnologische Mitteilungen | Arachnology Letters during the following year (2021) and will be available online. When preparing the manuscript, please, follow the Guidelines for Authors of this journal. Please, submit the manuscript to Peter Michalik (email@example.com). Deadline for submission is September 30, 2021.